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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0706.3314 | Vincent L. Fish | Vincent L. Fish, Lor\'ant O. Sjouwerman (NRAO) | Structure of W3(OH) from Very High Spectral Resolution Observations of 5
Centimeter OH Masers | 21 pages using emulateapj.cls including 16 figures and 2 tables,
accepted to ApJ | null | 10.1086/521096 | null | astro-ph | null | Recent studies of methanol and ground-state OH masers at very high spectral
resolution have shed new light on small-scale maser processes. The nearby
source W3(OH), which contains numerous bright masers in several different
transitions, provides an excellent laboratory for high spectral resolution
techniques. We present a model of W3(OH) based on EVN observations of the
rotationally-excited 6030 and 6035 MHz OH masers taken at 0.024 km/s spectral
resolution. The 6.0 GHz masers are becoming brighter with time and show
evidence for tangential proper motions. We confirm the existence of a region of
magnetic field oriented toward the observer to the southeast and find another
such region to the northeast in W3(OH), near the champagne flow. The 6.0 GHz
masers trace the inner edge of a counterclockwise rotating torus feature.
Masers at 6030 MHz are usually a factor of a few weaker than at 6035 MHz but
trace the same material. Velocity gradients of nearby Zeeman components are
much more closely correlated than in the ground state, likely due to the
smaller spatial separation between Zeeman components. Hydroxyl maser peaks at
very long baseline interferometric resolution appear to have structure on
scales both smaller than that resolvable as well as on larger scales.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:10:46 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Fish",
"Vincent L.",
"",
"NRAO"
],
[
"Sjouwerman",
"Loránt O.",
"",
"NRAO"
]
] |
0706.3315 | Elena G. Ferreiro | A. Capella, E. G. Ferreiro, A. Kaidalov and K. Tywoniuk | pi0 Fixed pT suppression and elliptic flow at LHC | 2 pages, 2 figures. Contributed to Workshop on Heavy Ion Collisions
at the LHC: Last Call for Predictions, Geneva, Switzerland, 14 May - 8 Jun
2007 | null | null | null | hep-ph | null | Using a final state interaction model which describes the data on these two
observables, at RHIC, we make predictions at the LHC -- using the same
cross-section and pT-shift. The increase in the medium density between these
two energies (by a factor close to three) produces an increase of the fixed pT
pi0 suppression by a factor 2 at large pT and of v2 by a factor 1.5.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 12:02:30 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Capella",
"A.",
""
],
[
"Ferreiro",
"E. G.",
""
],
[
"Kaidalov",
"A.",
""
],
[
"Tywoniuk",
"K.",
""
]
] |
0706.3316 | Stefan Ask | F. Anghinolfi, et al | Hadron beam test of a scintillating fibre tracker system for elastic
scattering and luminosity measurement in ATLAS | 12 pages, 8 figures. Submitted to Journal of Instrumentation (JINST) | JINST2:P07004,2007 | 10.1088/1748-0221/2/07/P07004 | null | physics.ins-det | null | A scintillating fibre tracker is proposed to measure elastic proton
scattering at very small angles in the ATLAS experiment at CERN. The tracker
will be located in so-called Roman Pot units at a distance of 240 m on each
side of the ATLAS interaction point. An initial validation of the design
choices was achieved in a beam test at DESY in a relatively low energy electron
beam and using slow off-the-shelf electronics. Here we report on the results
from a second beam test experiment carried out at CERN, where new detector
prototypes were tested in a high energy hadron beam, using the first version of
the custom designed front-end electronics. The results show an adequate
tracking performance under conditions which are similar to the situation at the
LHC. In addition, the alignment method using so-called overlap detectors was
studied and shown to have the expected precision.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 12:06:07 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Anghinolfi",
"F.",
""
]
] |
0706.3317 | Tiago Pereira | T. Pereira, M.S. Baptista, and J. Kurths | Detecting phase synchronization by localized maps: Application to neural
networks | null | Europhs. Lett. 77, 40006 (2007) | 10.1209/0295-5075/77/40006 | null | cond-mat.stat-mech cond-mat.other | null | We present an approach which enables to state about the existence of phase
synchronization in coupled chaotic oscillators without having to measure the
phase. This is done by observing the oscillators at special times, and
analyzing whether this set of points is localized. In particular, we show that
this approach is fruitful to analyze the onset of phase synchronization in
chaotic attractors whose phases are not well defined, as well as, in networks
of non-identical spiking/bursting neurons connected by chemical synapses.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 12:21:13 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Pereira",
"T.",
""
],
[
"Baptista",
"M. S.",
""
],
[
"Kurths",
"J.",
""
]
] |
0706.3318 | Benoit Claudon | Beno\^it Claudon (IECN) | Invariance of Gamma-dimension for projective families | withdrawn ; a mistake in the proof | null | null | null | math.AG math.CV | null | This article is withdrawn because of a mistake in the main result of the
paper.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 12:26:22 GMT"
},
{
"version": "v2",
"created": "Sun, 1 Jul 2007 12:48:13 GMT"
}
] | 2007-07-02T00:00:00 | [
[
"Claudon",
"Benoît",
"",
"IECN"
]
] |
0706.3319 | Burra Sidharth Gautam | Burra G.Sidharth | On the Photon Mass | 14 pages tex | null | null | IIAMIS-TR 0601 | physics.gen-ph | null | We review the case for the photon having a tiny mass compatible with the
experimental limits. We go over some possible experimental tests for such a
photon mass including the violation of Lorentz symmetry. We point out that such
violations may already have been witnessed in tests involving high energy gamma
rays from outer space as also ultra high energy cosmic rays.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 12:29:03 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Sidharth",
"Burra G.",
""
]
] |
0706.3320 | Tiago Pereira | T. Pereira, M.S. Baptista, J. Kurths | General Framework for phase synchronization through localized sets | null | null | 10.1103/PhysRevE.75.026216 | null | cond-mat.stat-mech | null | We present an approach which enables to identify phase synchronization in
coupled chaotic oscillators without having to explicitly measure the phase. We
show that if one defines a typical event in one oscillator and then observes
another one whenever this event occurs, these observations give rise to a
localized set. Our result provides a general and easy way to identify PS, which
can also be used to oscillators that possess multiple time scales. We
illustrate our approach in networks of chemically coupled neurons. We show that
clusters of phase synchronous neurons may emerge before the onset of phase
synchronization in the whole network, producing a suitable environment for
information exchanging. Furthermore, we show the relation between the localized
sets and the amount of information that coupled chaotic oscillator can
exchange.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 12:31:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Pereira",
"T.",
""
],
[
"Baptista",
"M. S.",
""
],
[
"Kurths",
"J.",
""
]
] |
0706.3321 | Surajit Sengupta | Jayee Bhattacharya (SNBNCBS, Kolkata), Arya Paul (SNBNCBS, Kolkata),
Surajit Sengupta (SNBNCBS, Kolkata) and Madan Rao (RRI & NCBS, Bangalore) | Elastoplastic model for the dynamics of solid-solid transformations :
role of non-affine deformation in microstructure selection | 18 pages 15 (eps) figures incorporated several referee comments | null | null | null | cond-mat.mtrl-sci | null | We study the nucleation dynamics of a model solid state transformation and
the criterion for microstructure selection using a molecular dynamics (MD)
simulation. Our simulations show a range of microstructures depending on the
depth of quench. We closely follow the dynamics of the solid and find that
transient {\em non-affine zones} (NAZ) are created at and evolve with the
rapidly moving transformation front. The dynamics of these plastic regions
determines the selection of microstructure. We formulate an {\it elastoplastic
model} which couples the elastic strain to the non-affine deformation, and
recover all the qualitative features of the MD simulation. Using this model, we
construct a dynamical phase diagram for microstructure selection, in addition
to making definite testable predictions.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 12:31:55 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Jun 2007 01:42:12 GMT"
},
{
"version": "v3",
"created": "Sat, 1 Mar 2008 05:04:27 GMT"
}
] | 2008-03-01T00:00:00 | [
[
"Bhattacharya",
"Jayee",
"",
"SNBNCBS, Kolkata"
],
[
"Paul",
"Arya",
"",
"SNBNCBS, Kolkata"
],
[
"Sengupta",
"Surajit",
"",
"SNBNCBS, Kolkata"
],
[
"Rao",
"Madan",
"",
"RRI & NCBS, Bangalore"
]
] |
0706.3322 | Julien Hendrickx | Vincent D. Blondel, Jean-Loup Guillaume, Julien M. Hendrickx and
Raphael M. Jungers | Distance distribution in random graphs and application to networks
exploration | 12 pages, 8 figures (18 .eps files) | null | 10.1103/PhysRevE.76.066101 | null | cond-mat.stat-mech cond-mat.dis-nn | null | We consider the problem of determining the proportion of edges that are
discovered in an Erdos-Renyi graph when one constructs all shortest paths from
a given source node to all other nodes. This problem is equivalent to the one
of determining the proportion of edges connecting nodes that are at identical
distance from the source node. The evolution of this quantity with the
probability of existence of the edges exhibits intriguing oscillatory behavior.
In order to perform our analysis, we introduce a new way of computing the
distribution of distances between nodes. Our method outperforms previous
similar analyses and leads to estimates that coincide remarkably well with
numerical simulations. It allows us to characterize the phase transitions
appearing when the connectivity probability varies.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 13:17:35 GMT"
},
{
"version": "v2",
"created": "Mon, 19 Nov 2007 13:12:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Blondel",
"Vincent D.",
""
],
[
"Guillaume",
"Jean-Loup",
""
],
[
"Hendrickx",
"Julien M.",
""
],
[
"Jungers",
"Raphael M.",
""
]
] |
0706.3323 | Tiago Pereira | T. Pereira, M.S. Baptista, J. Kurths, M.B. Reyes | Onset of Phase Synchronization in Neurons Conneted via Chemical Synapses | to appear in Int. J. Bif. Chaos | null | 10.1142/S0218127407019342 | null | cond-mat.stat-mech | null | We study the onset of synchronous states in realistic chaotic neurons coupled
by mutually inhibitory chemical synapses. For the realistic parameters, namely
the synaptic strength and the intrinsic current, this synapse introduces
non-coherences in the neuronal dynamics, yet allowing for chaotic phase
synchronization in a large range of parameters. As we increase the synaptic
strength, the neurons undergo to a periodic state, and no chaotic complete
synchronization is found.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 12:47:48 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Pereira",
"T.",
""
],
[
"Baptista",
"M. S.",
""
],
[
"Kurths",
"J.",
""
],
[
"Reyes",
"M. B.",
""
]
] |
0706.3324 | Tiago Pereira | T. Pereira, M. Thiel, M.S. Baptista, and J. Kurths | Network Mutual Information and Synchronization under Time
Transformations | 15 pg | null | 10.1088/1367-2630/10/8/083003 | null | cond-mat.stat-mech | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the effect of general time transformations on the phase
synchronization (PS) phenomenon and the mutual information rate (MIR) between
pairs of nodes in dynamical networks. We demonstrate two important results
concerning the invariance of both PS and the MIR. Under time transformations PS
can neither be introduced nor destroyed and the MIR cannot be raised from zero.
On the other hand, for proper time transformations the timing between the
cycles of the coupled oscillators can be largely improved. Finally, we discuss
the relevance of our findings for communication in dynamical networks.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 12:52:37 GMT"
},
{
"version": "v2",
"created": "Thu, 17 Jan 2008 17:14:59 GMT"
},
{
"version": "v3",
"created": "Thu, 17 Apr 2008 13:49:33 GMT"
},
{
"version": "v4",
"created": "Wed, 3 Sep 2008 16:57:05 GMT"
}
] | 2008-09-03T00:00:00 | [
[
"Pereira",
"T.",
""
],
[
"Thiel",
"M.",
""
],
[
"Baptista",
"M. S.",
""
],
[
"Kurths",
"J.",
""
]
] |
0706.3325 | Tiago Pereira | T. Pereira, M.S. Baptista, M.B. Reyes, I.L. Caldas, J.C. Sartorelli,
and J. Kurths | Global Bifurcation Destroying The Experimental Torus T2 | null | Phys. Rev E 73, 107201 (2006) | 10.1103/PhysRevE.73.017201 | null | nlin.CD | null | We show experimentally the scenario of a two-frequency torus $T^2$ breakdown,
in which a global bifurcation occurs due to the collision of a torus with an
unstable periodic orbit, creating a heteroclinic saddle connection, followed by
an intermittent behavior.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 13:00:28 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Pereira",
"T.",
""
],
[
"Baptista",
"M. S.",
""
],
[
"Reyes",
"M. B.",
""
],
[
"Caldas",
"I. L.",
""
],
[
"Sartorelli",
"J. C.",
""
],
[
"Kurths",
"J.",
""
]
] |
0706.3326 | Xinwei Zha | Xin-Wei Zha, Hai-Yang Song | Three-qubit pure-state canonical forms for Perfect Teleportation | 8 pages | null | null | null | quant-ph | null | Recently, Agrawal and Pati [Phys. Rev. A 74, 062320 (2006)] have given a
class of W-states that can be used for perfect teleportation. Here, two
canonical forms of perfect quantum channel are presented by transformation
operator and the GHZ state and the W state are special case of those two
canonical forms of perfect quantum channel. Furthermore, the orthogonal
complete measurement bases are given.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 13:03:27 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Zha",
"Xin-Wei",
""
],
[
"Song",
"Hai-Yang",
""
]
] |
0706.3327 | E. Ragoucy | E. Ragoucy and G. Satta | Analytical Bethe Ansatz for closed and open gl(M|N) super-spin chains in
arbitrary representations and for any Dynkin diagram | 40 pages; misprints and some references corrected; some mistakes in
the expression of the vacuum eigenvalue for the open case corrected (we are
grateful to R. Nepomechie who pointed them out) | JHEP 0709 : 001, 2007 | 10.1088/1126-6708/2007/09/001 | LAPTH-1189/07 | hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the analytical Bethe ansatz for spin chains based on the
superalgebras gl(M|N), $M\neq N$, with at each site an arbitrary representation
(and including inhomogeneities).
The calculation is done for closed and open spin chains. In this latter case,
the boundary matrices $K_{\pm}(u)$ are of general type, provided they commute.
We compute the Bethe ansatz equations in full generality, and for any type of
Dynkin diagram. Examples are worked out to illustrate the techniques.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 13:31:30 GMT"
},
{
"version": "v2",
"created": "Thu, 16 Aug 2007 15:16:27 GMT"
},
{
"version": "v3",
"created": "Thu, 17 Sep 2015 13:15:26 GMT"
}
] | 2015-09-18T00:00:00 | [
[
"Ragoucy",
"E.",
""
],
[
"Satta",
"G.",
""
]
] |
0706.3328 | M. S. Nanda Kumar | M. S. N. Kumar and S. Schmeja | The spatial distribution of substellar objects in IC348 and the Orion
Trapezium Cluster | 4 pages. Accepted by A&A Letters | Astron.Astrophys. 471 (2007) L33 | 10.1051/0004-6361:20077875 | null | astro-ph | null | Aims: Some theoretical scenarios suggest the formation of brown dwarfs as
ejected stellar embryos in star-forming clusters. Such a formation mechanism
can result in different spatial distributions of stars and substellar objects.
We aim to investigate the spatial structure of stellar and substellar objects
in two well sampled and nearby embedded clusters, namely IC348 and the Orion
Trapezium Cluster (OTC) to test this hypothesis. Methods:Deep near-infrared
K-band data complete enough to sample the substellar population in IC348 and
OTC are obtained from the literature. The spatial distribution of the K-band
point sources is analysed using the Minimum Spanning Tree (MST) method. The Q
parameter and the spanning trees are evaluated for stellar and substellar
objects as a function of cluster core radius R$_c$. Results: The stellar
population in both IC348 and OTC display a clustered distribution whereas the
substellar population is distributed homogeneously in space within twice the
cluster core radius. Although the substellar objects do not appear to be bound
by the cluster potential well, they are still within the limits of the cluster
and not significantly displaced from their birth sites. Conclusions: The
spatially homogeneous distribution of substellar objects is best explained by
assuming higher initial velocities, distributed in a random manner and going
through multiple interactions. The overall spatial coincidence of these objects
with the cluster locations can be understood if these objects are nevertheless
travelling slowly enough so as to feel the gravitational effect of the cluster.
The observations support the formation of substellar objects as ``ejected
stellar embryos''. Higher ejection velocities are necessary but net spatial
displacements may not be necessary to explain the observational data.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 13:26:15 GMT"
}
] | 2008-03-13T00:00:00 | [
[
"Kumar",
"M. S. N.",
""
],
[
"Schmeja",
"S.",
""
]
] |
0706.3329 | Miguel Angel Martin-Delgado | A. Bermudez, M.A. Martin-Delgado, E. Solano | Dirac Cat States in Relativistic Landau Levels | Revtex4, color figures, submitted for publication | Phys. Rev. Lett. 99, 123602 (2007). | 10.1103/PhysRevLett.99.123602 | null | quant-ph cond-mat.mes-hall hep-th | null | We show that a relativistic version of Schrodinger cat states, here called
Dirac cat states, can be built in relativistic Landau levels when an external
magnetic field couples to a relativistic spin 1/2 charged particle. Under
suitable initial conditions, the associated Dirac equation produces unitarily
Dirac cat states involving the orbital quanta of the particle in a well defined
mesoscopic regime. We demonstrate that the proposed Dirac cat states have a
purely relativistic origin and cease to exist in the non-relativistic limit. In
this manner, we expect to open relativistic quantum mechanics to the rich
structures of quantum optics and quantum information.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 13:28:36 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Bermudez",
"A.",
""
],
[
"Martin-Delgado",
"M. A.",
""
],
[
"Solano",
"E.",
""
]
] |
0706.3330 | Ashley Willis | A. P. Willis and R. R. Kerswell | Coherent structures in localised and global pipe turbulence | As accepted for PRL. 4 pages, 6 figures. Alterations to figs. 4,5.
Significant changes to text | null | null | null | physics.flu-dyn | null | The recent discovery of unstable travelling waves (TWs) in pipe flow has been
hailed as a significant breakthrough with the hope that they populate the
turbulent attractor. We confirm the existence of coherent states with internal
fast and slow streaks commensurate in both structure and energy with known TWs
using numerical simulations in a long pipe. These only occur, however, within
less energetic regions of (localized) `puff' turbulence at low Reynolds numbers
(Re=2000-2400), and not at all in (homogeneous) `slug' turbulence at Re=2800.
This strongly suggests that all currently known TWs sit in an intermediate
region of phase space between the laminar and turbulent states rather than
being embedded within the turbulent attractor itself. New coherent fast streak
states with strongly decelerated cores appear to populate the turbulent
attractor instead.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 13:49:40 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Feb 2008 14:41:41 GMT"
}
] | 2008-02-20T00:00:00 | [
[
"Willis",
"A. P.",
""
],
[
"Kerswell",
"R. R.",
""
]
] |
0706.3331 | Anna Bai | Yunfen Bai (1 and 2), Xinhua Hu (1), Zhongxing Ye (1) ((1)Department
of Mathematics, Shanghai Jiaotong University; (2)Department of Mathematics,
Shijiazhuang College) | A Model for Counterparty Risk with Geometric Attenuation Effect and the
Valuation of CDS | 8 pages | null | null | null | q-fin.RM math.PR | null | In this paper, a geometric function is introduced to reflect the attenuation
speed of impact of one firm's default to its partner. If two firms are
competitions (copartners), the default intensity of one firm will decrease
(increase) abruptly when the other firm defaults. As time goes on, the impact
will decrease gradually until extinct. In this model, the joint distribution
and marginal distributions of default times are derived by employing the change
of measure, so can we value the fair swap premium of a CDS.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 13:44:05 GMT"
}
] | 2008-12-02T00:00:00 | [
[
"Bai",
"Yunfen",
"",
"1 and 2"
],
[
"Hu",
"Xinhua",
""
],
[
"Ye",
"Zhongxing",
""
]
] |
0706.3332 | In\'es Crespo-Chac\'on | I. Crespo-Chac\'on (1 and 2), G. Micela (1), F. Reale (1 and 3), M.
Caramazza (1 and 3), J. L\'opez-Santiago (1 and 2), I. Pillitteri (3) ((1)
INAF - Osservatorio Astronomico di Palermo, (2) Departamento de Astrof\'isica
y Ciencias de la Atm\'osfera, Universidad Complutense de Madrid, (3)
Dipartimento di Scienze Fisiche ed Astronomiche, Universit\`a di Palermo) | X-ray flares on the UV Ceti-type star CC Eridani: a "peculiar"
time-evolution of spectral parameters | 14 pages, 12 figures. Accepted for publication in Astronomy &
Astrophysics | null | 10.1051/0004-6361:20077601 | null | astro-ph | null | Context: Weak flares are supposed to be an important heating agent of the
outer layers of stellar atmospheres. However, due to instrumental limitations,
only large X-ray flares have been studied in detail until now.
Aims: We used an XMM-Newton observation of the very active BY-Dra type binary
star CC Eri in order to investigate the properties of two flares that are
weaker than those typically studied in the literature.
Methods: We performed time-resolved spectroscopy of the data taken with the
EPIC-PN CCD camera. A multi-temperature model was used to fit the spectra. We
inferred the size of the flaring loops using the density-temperature diagram.
The loop scaling laws were applied for deriving physical parameters of the
flaring plasma. We also estimated the number of loops involved in the observed
flares.
Results: A large X-ray variability was found. Spectral analysis showed that
all the regions in the light curve, including the flare segments, are
well-described by a 3-T model with variable emission measures but,
surprisingly, with constant temperatures (values of 3, 10 and 22 MK). The
analysed flares lasted ~ 3.4 and 7.1 ks, with flux increases of factors
1.5-1.9. They occurred in arcades made of a few tens of similar coronal loops.
The size of the flaring loops is much smaller than the distance between the
stellar surfaces in the binary system, and even smaller than the radius of each
of the stars. The obtained results are consistent with the following ideas: (i)
the whole X-ray light curve of CC Eri could be the result of a superposition of
multiple low-energy flares, and (ii) stellar flares can be scaled-up versions
of solar flares.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 16:45:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Crespo-Chacón",
"I.",
"",
"1 and 2"
],
[
"Micela",
"G.",
"",
"1 and 3"
],
[
"Reale",
"F.",
"",
"1 and 3"
],
[
"Caramazza",
"M.",
"",
"1 and 3"
],
[
"López-Santiago",
"J.",
"",
"1 and 2"
],
[
"Pillitteri",
"I.",
""
]
] |
0706.3333 | Yohan Payan | P. Mozer (TIMC - Imag), A. Leroy (TIMC - Imag), Yohan Payan (TIMC -
Imag), J. Troccaz (TIMC - Imag), E. Chartier-Kastler, F. Richard | Computer-assisted access to the kidney | null | International Journal of Medical Robotics and Computer Assisted
Surgery 1, 4 (12/2005) 58-66 | 10.1002/rcs.58 | null | physics.med-ph | null | OBJECTIVES: The aim of this paper is to introduce the principles of
computer-assisted access to the kidney. The system provides the surgeon with a
pre-operative 3D planning on computed tomography (CT) images. After a rigid
registration with space-localized ultrasound (US) data, preoperative planning
can be transferred to the intra-operative conditions and an intuitive
man-machine interface allows the user to perform a puncture. MATERIAL AND
METHODS: Both CT and US images of informed normal volunteer were obtained to
perform calculation on the accuracy of registration and punctures were carried
out on a kidney phantom to measure the precision of the whole of the system.
RESULTS: We carried out millimetric registrations on real data and guidance
experiments on a kidney phantom showed encouraging results of 4.7 mm between
planned and reached targets. We noticed that the most significant error was
related to the needle deflection during the puncture. CONCLUSION: Preliminary
results are encouraging. Further work will be undertaken to improve efficiency
and accuracy, and to take breathing into account.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 13:54:49 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Mozer",
"P.",
"",
"TIMC - Imag"
],
[
"Leroy",
"A.",
"",
"TIMC - Imag"
],
[
"Payan",
"Yohan",
"",
"TIMC -\n Imag"
],
[
"Troccaz",
"J.",
"",
"TIMC - Imag"
],
[
"Chartier-Kastler",
"E.",
""
],
[
"Richard",
"F.",
""
]
] |
0706.3334 | Gregory Marc Miermont | Gr\'egory Miermont (LM-Orsay), Mathilde Weill (DMA) | Radius and profile of random planar maps with faces of arbitrary degrees | 25 pages, 2 figures | null | null | null | math.PR | null | We prove some asymptotic results for the radius and the profile of large
random rooted planar maps with faces of arbitrary degrees. Using a bijection
due to Bouttier, Di Francesco and Guitter between rooted planar maps and
certain four-type trees with positive labels, we derive our results from a
conditional limit theorem for four-type spatial Galton-Watson trees.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 13:55:45 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Miermont",
"Grégory",
"",
"LM-Orsay"
],
[
"Weill",
"Mathilde",
"",
"DMA"
]
] |
0706.3335 | Bernard Hanzon | Bernard Hanzon and Wolfgang Scherrer | Filtering and estimation in stochastic volatility models with rationally
distributed disturbances | null | null | null | null | math.OC math.ST stat.TH | null | This paper deals with the filtering problem for a class of discrete time
stochastic volatility models in which the disturbances have rational
probability density functions. This includes the Cauchy distributions and
Student t-distributions with odd number of degrees of freedom. Using state
space realizations to represent the rational probability density functions we
are able to solve the filtering problem exactly. However the size of the
involved state space matrices grows exponentially with each time step of the
filter. Therefore we use stochastically balanced truncation techniques to
approximate the high order rational functions involved. In a simulation study
we show the applicability of this approach. In addition a simple method of
moments estimator is derived.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 13:59:10 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Hanzon",
"Bernard",
""
],
[
"Scherrer",
"Wolfgang",
""
]
] |
0706.3336 | Gaetan Chenevier | Gaetan Chenevier, Laurent Clozel | Corps de nombres peu ramifies et formes automorphes autoduales | 50 pages, french. Section 4.18 has been extended : let F be a totally
real field and \pi a selfdual cuspidal automorphic representation of
GL(2n,A_F) which is cohomological at all the archimedean places and discrete
at a finite place at least, we show that for each place v the L-parameter of
\pi_v preserves a non-degenerate symplectic pairing | null | null | null | math.NT math.RT | null | Let S be a finite set of primes, p in S, and Q_S a maximal algebraic
extension of Q unramified outside S and infinity. Assume that |S|>=2. We show
that the natural maps Gal(Q_p^bar/Q_p) --> Gal(Q_S/Q) are injective. Much of
the paper is devoted to the problem of constructing selfdual automorphic
cuspidal representations of GL(2n,A_Q) with prescribed properties at all
places, that we study via the twisted trace formula of J. Arthur. The
techniques we develop shed also some lights on the orthogonal/symplectic
alternative for selfdual representations of GL(2n).
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:09:50 GMT"
},
{
"version": "v2",
"created": "Sat, 15 Sep 2007 13:29:36 GMT"
}
] | 2007-09-15T00:00:00 | [
[
"Chenevier",
"Gaetan",
""
],
[
"Clozel",
"Laurent",
""
]
] |
0706.3337 | Carina Boyallian | Carina Boyallian and Vanesa Meinardi | Quasifinite representations of the Lie superalgebra of quantum pseudo
differential operators | 23 pages | null | 10.1063/1.2834919 | null | math-ph math.MP | null | In this paper we extend general results obtained by V. Kac and J. Liberati,
in "Unitary quasifinite representations of $W_\infty$", (Letters Math. Phys.,
53 (2000), 11-27), for quasifinite highest weight representations of
$\Z$-graded Lie algebras to ${1/2}\Z$-graded Lie superalgebras, and we apply
these to classify the irreducible quasifinite highest weight modules of the Lie
superalgebra of quantum pseudo-differential operators.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:04:20 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Boyallian",
"Carina",
""
],
[
"Meinardi",
"Vanesa",
""
]
] |
0706.3338 | Stephen Pride | Stephen J Pride | On the residual finiteness and other properties of (relative)
one-relator groups | null | null | null | null | math.GR | null | A relative one-relator presentation has the form P = < X,H ; R > where X is a
set, H is a group, and R is a group word on X and H. We show that if the group
word on X obtained from R by deleting all the terms from H has what we call the
unique max-min property, then the group defined by P is residually finite if
and only if H is residually finite (Theorem 1). We apply this to obtain new
results concerning the residual finiteness of (ordinary) one-relator groups
(Theorem 4). We also obtain results concerning the conjugacy problem for
one-relator groups (Theorem 5), and results concerning the relative asphericity
of presentations of the form P (Theorem 6).
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:07:08 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Pride",
"Stephen J",
""
]
] |
0706.3339 | Nikhil Jethava Mr. | N. Jethava, C. Henkel, K.M. Menten, C.L. Carilli, and M.J. Reid | Redshifted formaldehyde from the gravitational lens B0218+357 | Accepted for A&A, 8 Pages, 3 Figures, 5 Tables | null | 10.1051/0004-6361:20077353 | null | astro-ph | null | The gravitational lens toward B0218+357 offers the unique possibility to
study cool moderately dense gas with high sensitivity and angular resolution in
a cloud that existed half a Hubble time ago. Observations of the radio
continuum and six formaldehyde (H2CO) lines were carried out with the VLA, the
Plateau de Bure interferometer, and the Effelsberg 100-m telescope. Three radio
continuum maps indicate a flux density ratio between the two main images, A and
B, of ~ 3.4 +/- 0.2. Within the errors the ratio is the same at 8.6, 14.1, and
43 GHz. The 1_{01}-0_{00} line of para-H2CO is shown to absorb the continuum of
image A. Large Velocity Gradient radiative transfer calculations are performed
to reproduce the optical depths of the observed two cm-wave "K-doublet" and
four mm-wave rotational lines. These calculations also account for a likely
frequency-dependent continuum cloud coverage. Confirming the diffuse nature of
the cloud, an n(H2) density of < 1000 cm^{-3} is derived, with the best fit
suggesting n(H2) ~ 200 cm^{-3}. The H2CO column density of the main velocity
component is ~5 * 10^{13} cm^{-2}, to which about 7.5 * 10^{12} cm^{-2} has to
be added to also account for a weaker feature on the blue side, 13 km/s apart.
N(H2CO)/N(NH3) ~ 0.6, which is four times less than the average ratio obtained
from a small number of local diffuse (galactic) clouds seen in absorption. The
ortho-to-para H2CO abundance ratio is 2.0 - 3.0, which is consistent with the
kinetic temperature of the molecular gas associated with the lens of B0218+357.
With the gas kinetic temperature and density known, it is found that optically
thin transitions of CS, HCN, HNC, HCO+, and N2H+ (but not CO) will provide
excellent probes of the cosmic microwave background at redshift z=0.68.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:03:30 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Jun 2007 17:35:54 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Jethava",
"N.",
""
],
[
"Henkel",
"C.",
""
],
[
"Menten",
"K. M.",
""
],
[
"Carilli",
"C. L.",
""
],
[
"Reid",
"M. J.",
""
]
] |
0706.3340 | S. L. Bud'ko | I.S. Veschunov, L.Ya. Vinnikov, S.L. Bud'ko, P.C. Canfield | Visualization of ferromagnetic domains in TbNi$_2$B$_2$C and
ErNi$_2$B$_2$C single crystals: Weak ferromagnetism and its coexistence with
superconductivity | null | null | 10.1103/PhysRevB.76.174506 | null | cond-mat.supr-con | null | The magnetic flux structure in the basal plane, (001), of single crystals of
superconducting (R = Er) and non-superconducting (R = Tb) RNi$_2$B$_2$C was
studied by high resolution Bitter decoration at temperatures below $T_c$
(superconducting transition) and/or $T_N$ (antiferromagnetic transition). For
both materials two sets of domain boundaries, in \{110\} and \{100\} planes,
were observed. The temperature ranges in which the \{100\} domain boundaries
were observed in TbNi$_2$B$_2$C and ErNi$_2$B$_2$C coincide with the weak
ferromagnetic (WFM) ordering in these materials. On the other hand, the \{110\}
twin boundaries - the antiferromagnetic domain boundaries - were observed in
both compounds below $T_N$. The possibility of interpretation of \{100\}
boundaries as Bloch domain walls in the weakly ferromagnetic phase, for $T <
T_{WFM} < T_N$ (TbNi$_2$B$_2$C) or $T < T_{WFM} < T_N < T_c$ (ErNi$_2$B$_2$C)
is discussed.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:07:34 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Veschunov",
"I. S.",
""
],
[
"Vinnikov",
"L. Ya.",
""
],
[
"Bud'ko",
"S. L.",
""
],
[
"Canfield",
"P. C.",
""
]
] |
0706.3341 | Christophe Fouquere | Christophe Fouquer\'e (LIPN) | A Sequent Calculus for Modelling Interferences | null | null | null | null | cs.LO | null | A logic calculus is presented that is a conservative extension of linear
logic. The motivation beneath this work concerns lazy evaluation, true
concurrency and interferences in proof search. The calculus includes two new
connectives to deal with multisequent structures and has the cut-elimination
property. Extensions are proposed that give first results concerning our
objectives.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:24:34 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Fouqueré",
"Christophe",
"",
"LIPN"
]
] |
0706.3342 | Peter B. Weichman | Marissa L. Weichman | The Forgotten Night: The Number Devil Explores Spherical Geometry | 10 pages, 15 figures, submitted to American Journal of Physics | null | null | null | math.HO physics.ed-ph | null | This is a missing chapter from Hans Magnus Enzensberger's mathematical
adventure The Number Devil (Henry Holt and Company, New York, 1997). In the
book, a math-hating boy named Robert is visited in his dreams by the clever
Number Devil, who teaches him to love all things numerical. However, we all
forget our dreams from time to time. Here is one adventure that Enzensberger
overlooked, where the Number Devil introduces Robert to geometry not-of-Euclid,
great circles, parallel transport, the pendulum of Foucault, and the genius of
Euler.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:29:06 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Weichman",
"Marissa L.",
""
]
] |
0706.3343 | Ernesto Mordecki | Felipe Cucker and Ernesto Mordecki | Flocking in noisy environments | null | null | null | null | math.DS math.PR | null | We consider a perturbed version of the dynamics of a flock introduced by
Cucker and Smale ("Emergent behaviour in flocks") and prove, under similar
conditions, that nearly-alignment (a concept that is precised in the text) is
achieved with a certain probability, bounded from below.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:32:04 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Cucker",
"Felipe",
""
],
[
"Mordecki",
"Ernesto",
""
]
] |
0706.3344 | Michael F. Bietenholz | M. F. Bietenholz and N. Bartel | SN 2001em: No Jet-Driven Gamma Ray Burst Event | 5 pages, 2 figs, accepted for publication in ApJ Letters; added
references | null | 10.1086/521048 | null | astro-ph | null | We report on our second-epoch VLBI and VLA observations of the Type Ib/c
supernova 2001em, five years after the explosion. It was suggested that SN
2001em might be a jet-driven gamma ray burst (GRB), with the jet oriented near
the plane of the sky, which would entail relativistic expansion or motion. Our
VLBI image shows that SN 2001em is still unresolved five years after the
explosion. For a distance of 83 Mpc (H_0 = 70 km/s/Mpc), the nominal expansion
velocity is 5800 +/- 10,000 km/s, and the proper motion is 33,000 +/- 34,000
km/s. Our values are inconsistent with either relativistic expansion or motion,
but are consistent with the non-relativistic expansion speeds and small proper
motions seen in other supernovae. In particular these values are consistent
with radio emission from SN 2001em being due to normal, non-relativistic
supernova ejecta interacting with the circumstellar medium. Our VLA
observations show a power-law decay in flux density since the time of the peak
in the 8.4 GHz radio lightcurve in ~2003.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:50:11 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 07:26:18 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bietenholz",
"M. F.",
""
],
[
"Bartel",
"N.",
""
]
] |
0706.3345 | Zahra-Sadat Yamani | Z. Yamani, W.J.L. Buyers, R.A. Cowley and D. Prabhakaran | Orbital and Spin Excitations in Cobalt Oxide | To be published in Physica B (Proceedings of SCES07 conference in
Houston) | Physica B 403 (2008) p. 1406 | 10.1016/j.physb.2007.10.306 | null | cond-mat.str-el | null | By means of neutron scattering we have determined new branches of magnetic
excitations in orbitally active CoO (TN=290 K) up to 15 THz and for
temperatures from 6 K to 450 K. Data were taken in the (111) direction in six
single-crystal zones. From the dependence on temperature and Q we have
identified several branches of magnetic excitation. We describe a model for the
coupled orbital and spin states of Co2+ subject to a crystal field and
tetragonal distortion.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:46:29 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Yamani",
"Z.",
""
],
[
"Buyers",
"W. J. L.",
""
],
[
"Cowley",
"R. A.",
""
],
[
"Prabhakaran",
"D.",
""
]
] |
0706.3346 | William Chaplin | N. J. Tarrant, W. J. Chaplin, Y. Elsworth, S. A. Spreckley, I. R.
Stevens | Asteroseismology of red giants: photometric observations of Arcturus by
SMEI | 6 pages, 5 figures; accepted for publication in MNRAS Letters | null | 10.1111/j.1745-3933.2007.00387.x | null | astro-ph | null | We present new results on oscillations of the K1.5 III giant Arcturus (alpha
Boo), from analysis of just over 2.5 yr of precise photometric observations
made by the Solar Mass Ejection Imager (SMEI) on board the Coriolis satellite.
A strong mode of oscillation is uncovered by the analysis, having frequency
3.51+/-0.03 micro-Hertz. By fitting its mode peak, we are able offer a highly
constrained direct estimate of the damping time (tau = 24+/-1 days). The data
also hint at the possible presence of several radial-mode overtones, and maybe
some non-radial modes. We are also able to measure the properties of the
granulation on the star, with the characteristic timescale for the granulation
estimated to be 0.50+/-0.05 days.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:37:46 GMT"
},
{
"version": "v2",
"created": "Tue, 28 Aug 2007 11:37:02 GMT"
},
{
"version": "v3",
"created": "Tue, 2 Oct 2007 12:54:54 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Tarrant",
"N. J.",
""
],
[
"Chaplin",
"W. J.",
""
],
[
"Elsworth",
"Y.",
""
],
[
"Spreckley",
"S. A.",
""
],
[
"Stevens",
"I. R.",
""
]
] |
0706.3347 | Sergei Sergeev | Stephane Gaubert and Sergei Sergeev | Cyclic projectors and separation theorems in idempotent convex geometry | 20 pages, 1 figure | Journal of Mathematical Sciences (Springer, New-York), Vol. 155,
No. 6, pp.815--829. Translated from Fundamentalnaya i Prikladnaya Matematika,
Vol. 13, No. 4, pp. 31\^a?"52, 2007. | 10.1007/s10958-008-9243-8 | null | math.MG | null | Semimodules over idempotent semirings like the max-plus or tropical semiring
have much in common with convex cones. This analogy is particularly apparent in
the case of subsemimodules of the n-fold cartesian product of the max-plus
semiring it is known that one can separate a vector from a closed subsemimodule
that does not contain it. We establish here a more general separation theorem,
which applies to any finite collection of closed semimodules with a trivial
intersection. In order to prove this theorem, we investigate the spectral
properties of certain nonlinear operators called here idempotent cyclic
projectors. These are idempotent analogues of the cyclic nearest-point
projections known in convex analysis. The spectrum of idempotent cyclic
projectors is characterized in terms of a suitable extension of Hilbert's
projective metric. We deduce as a corollary of our main results the idempotent
analogue of Helly's theorem.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:42:03 GMT"
}
] | 2009-07-10T00:00:00 | [
[
"Gaubert",
"Stephane",
""
],
[
"Sergeev",
"Sergei",
""
]
] |
0706.3348 | Genaro Juarez Martinez | Genaro Juarez Martinez, Harold V. McIntosh, Juan C. Seck Tuoh Mora and
Sergio V. Chapa Vergara | Determining a regular language by glider-based structures called phases
fi_1 in Rule 110 | by publish in Journal of Cellular Automata | null | null | null | nlin.CG | null | Rule 110 is a complex elementary cellular automaton able of supporting
universal computation and complicated collision-based reactions between
gliders. We propose a representation for coding initial conditions by means of
a finite subset of regular expressions. The sequences are extracted both from
de Bruijn diagrams and tiles specifying a set of phases fi_1 for each glider in
Rule 110. The subset of regular expressions is explained in detail.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:54:25 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Martinez",
"Genaro Juarez",
""
],
[
"McIntosh",
"Harold V.",
""
],
[
"Mora",
"Juan C. Seck Tuoh",
""
],
[
"Vergara",
"Sergio V. Chapa",
""
]
] |
0706.3349 | Herbert Muthsam | H. J. Muthsam, B. Loew-Baselli, Chr. Obertscheider, M. Langer, P.
Lenz, F. Kupka | High-resolution models of solar granulation: the 2D case | null | null | 10.1111/j.1365-2966.2007.12185.x | null | astro-ph | null | Using grid refinement, we have simulated solar granulation in 2D. The refined
region measures 1.97*2.58 Mm (vertical*horizontal). Grid spacing there is
1.82*2.84 km. The downflows exhibit strong Kelvin-Helmholtz instabilities.
Below the photosphere, acoustic pulses are generated. They proceed laterally
(in some cases distances of at least the size of our refined domain) and may be
enhanced when transversing downflows) as well as upwards where, in the
photosphere they contribute significantly to 'turbulence' (velocity gradients,
etc.) The acoustic pulses are ubiquitous in that at any time several of them
are seen in our high-resolution domain. Their possible contributions to p-mode
excitation or heating of the chromosphere needs to be investigated.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 14:58:24 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Muthsam",
"H. J.",
""
],
[
"Loew-Baselli",
"B.",
""
],
[
"Obertscheider",
"Chr.",
""
],
[
"Langer",
"M.",
""
],
[
"Lenz",
"P.",
""
],
[
"Kupka",
"F.",
""
]
] |
0706.3350 | Veronika Rehn-Sonigo | Veronika Rehn-Sonigo (INRIA Rh\^one-Alpes, LIP) | Optimal Replica Placement in Tree Networks with QoS and Bandwidth
Constraints and the Closest Allocation Policy | null | null | null | null | cs.DC | null | This paper deals with the replica placement problem on fully homogeneous tree
networks known as the Replica Placement optimization problem. The client
requests are known beforehand, while the number and location of the servers are
to be determined. We investigate the latter problem using the Closest access
policy when adding QoS and bandwidth constraints. We propose an optimal
algorithm in two passes using dynamic programming.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:01:35 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 14:06:26 GMT"
},
{
"version": "v3",
"created": "Thu, 28 Jun 2007 15:24:39 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Rehn-Sonigo",
"Veronika",
"",
"INRIA Rhône-Alpes, LIP"
]
] |
0706.3351 | Barbara Drossel | Barbara Drossel | Random Boolean Networks | This is a review on Random Boolean Networks. The new version now
includes a proper title page. The main body is unchanged | Published in "Reviews of Nonlinear Dynamics and Complexity" Vol.1,
Ed. HG Schuster (Wiley, 2008) | null | null | cond-mat.stat-mech cond-mat.dis-nn | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This review explains in a self-contained way the properties of random Boolean
networks and their attractors, with a special focus on critical networks. Using
small example networks, analytical calculations, phenomenological arguments,
and problems to solve, the basic concepts are introduced and important results
concerning phase diagrams, numbers of relevant nodes and attractor properties
are derived.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:02:10 GMT"
},
{
"version": "v2",
"created": "Fri, 14 Nov 2008 10:33:52 GMT"
}
] | 2008-11-14T00:00:00 | [
[
"Drossel",
"Barbara",
""
]
] |
0706.3352 | Sundaram Thangavelu | B. Rajeev and S. Thangavelu | Probabilistic Representations of Solutions of the Forward Equations | 29 pages | null | null | null | math.PR math.AP | null | In this paper we prove a stochastic representation for solutions of the
evolution equation $ \partial_t \psi_t = {1/2}L^*\psi_t $ where $ L^* $ is the
formal adjoint of an elliptic second order differential operator with smooth
coefficients corresponding to the infinitesimal generator of a finite
dimensional diffusion $ (X_t).$ Given $ \psi_0 = \psi $, a distribution with
compact support, this representation has the form $ \psi_t = E(Y_t(\psi))$
where the process $ (Y_t(\psi))$ is the solution of a stochastic partial
differential equation connected with the stochastic differential equation for $
(X_t) $ via Ito's formula.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:17:12 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Rajeev",
"B.",
""
],
[
"Thangavelu",
"S.",
""
]
] |
0706.3353 | Roland Bastardis | Roland Bastardis, Nathalie Guihery, Coen de Graaf | Microscopic origin of isotropic non-Heisenberg behavior in highly
correlated systems | 4 pages, 3 figures | null | 10.1103/PhysRevB.76.132412 | null | cond-mat.str-el | null | We have reanalyzed the microscopic origin of the isotropic deviations that
are observed from the energy spacings predicted by the HDVV Hamiltonian.
Usually, a biquadratic spin operator is added to the HDVV Hamiltonian to
account for such deviations. It is shown here that this operator cannot
describe the effect of the excited atomic non-Hund states which brought the
most important contribution to the deviations. For systems containing more than
two magnetic centers, non-Hund states cause additional interactions that are of
the same order of magnitude as the biquadratic exchange and should have
significant effects on the macroscopic properties of extended systems.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:23:35 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bastardis",
"Roland",
""
],
[
"Guihery",
"Nathalie",
""
],
[
"de Graaf",
"Coen",
""
]
] |
0706.3354 | Andr\'e Saraiva | A. L. Saraiva, M. J. Calderon and Belita Koiller | Reliability of the Heitler-London approach for the exchange coupling
between electrons in semiconductor nanostructures | 5 pages, 4 Postscript figures, to be published in Phys. Rev. B | Phys. Rev. B 76, 233302 (2007) | 10.1103/PhysRevB.76.233302 | null | cond-mat.other cond-mat.mes-hall quant-ph | null | We calculate the exchange coupling J between electrons in a double-well
potential in a two-dimensional semiconductor environment within the
Heitler-London (HL) approach. Two functional forms are considered for the
double-well potential. We show that by choosing an appropriate and relatively
simple single-electron variational wave function it is possible, within the HL
approach, to significantly improve the estimates for J. In all cases the
present scheme overcomes the artifacts and limitations at short interdot
distances, previously attributed to the HL method, where unphysical triplet
ground states have been found, and leads to an overall agreement with analytic
interpolated expressions for J obtained for a donor-type model potential.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:53:42 GMT"
},
{
"version": "v2",
"created": "Wed, 28 Nov 2007 20:10:35 GMT"
}
] | 2008-01-16T00:00:00 | [
[
"Saraiva",
"A. L.",
""
],
[
"Calderon",
"M. J.",
""
],
[
"Koiller",
"Belita",
""
]
] |
0706.3355 | Samuel Lopes | Paula A.A.B. Carvalho and Samuel A. Lopes | Automorphisms of Generalized Down-Up Algebras | 20 pages | null | null | null | math.RA math.RT | null | A generalization of down-up algebras was introduced by Cassidy and Shelton
(J. Algebra 279 (2004), no. 1), the so-called generalized down-up algebras. We
describe the automorphism group of conformal Noetherian generalized down-up
algebras L(f,r,s,\gamma) such that r is not a root of unity, listing explicitly
the elements of the group. In the last section we apply these results to
Noetherian down-up algebras, thus obtaining a characterization of the
automorphism group of Noetherian down-up algebras A(\alpha, \beta, \gamma) for
which the roots of the polynomial X^2-\alpha X-\beta are not both roots of
unity.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:28:48 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Carvalho",
"Paula A. A. B.",
""
],
[
"Lopes",
"Samuel A.",
""
]
] |
0706.3356 | Pablo P. Yepes | A. J. Baltz, G. Baur, D. d'Enterria, L. Frankfurt, F. Gelis, V. Guzey,
K. Hencken, Yu. Kharlov, M. Klasen, S. R. Klein, V. Nikulin, J. Nystrand, I.
A. Pshenichnov, S. Sadovsky, E. Scapparone, J. Seger, M. Strikman, M.
Tverskoy, R. Vogt, S. N. White, U. A. Wiedemann, P. Yepes, M. Zhalov | The Physics of Ultraperipheral Collisions at the LHC | 229 Pages, 121 figures | Phys.Rept.458:1-171,2008 | 10.1016/j.physrep.2007.12.001 | null | nucl-ex hep-ex hep-ph nucl-th | null | We discuss the physics of large impact parameter interactions at the LHC:
ultraperipheral collisions (UPCs). The dominant processes in UPCs are
photon-nucleon (nucleus) interactions. The current LHC detector configurations
can explore small $x$ hard phenomena with nuclei and nucleons at photon-nucleon
center-of-mass energies above 1 TeV, extending the $x$ range of HERA by a
factor of ten. In particular, it will be possible to probe diffractive and
inclusive parton densities in nuclei using several processes. The interaction
of small dipoles with protons and nuclei can be investigated in elastic and
quasi-elastic $J/\psi$ and $\Upsilon$ production as well as in high $t$
$\rho^0$ production accompanied by a rapidity gap. Several of these phenomena
provide clean signatures of the onset of the new high gluon density QCD regime.
The LHC is in the kinematic range where nonlinear effects are several times
larger than at HERA. Two-photon processes in UPCs are also studied. In
addition, while UPCs play a role in limiting the maximum beam luminosity, they
can also be used a luminosity monitor by measuring mutual electromagnetic
dissociation of the beam nuclei. We also review similar studies at HERA and
RHIC as well as describe the potential use of the LHC detectors for UPC
measurements.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:15:47 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Jun 2007 19:44:12 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Baltz",
"A. J.",
""
],
[
"Baur",
"G.",
""
],
[
"d'Enterria",
"D.",
""
],
[
"Frankfurt",
"L.",
""
],
[
"Gelis",
"F.",
""
],
[
"Guzey",
"V.",
""
],
[
"Hencken",
"K.",
""
],
[
"Kharlov",
"Yu.",
""
],
[
"Klasen",
"M.",
""
],
[
"Klein",
"S. R.",
""
],
[
"Nikulin",
"V.",
""
],
[
"Nystrand",
"J.",
""
],
[
"Pshenichnov",
"I. A.",
""
],
[
"Sadovsky",
"S.",
""
],
[
"Scapparone",
"E.",
""
],
[
"Seger",
"J.",
""
],
[
"Strikman",
"M.",
""
],
[
"Tverskoy",
"M.",
""
],
[
"Vogt",
"R.",
""
],
[
"White",
"S. N.",
""
],
[
"Wiedemann",
"U. A.",
""
],
[
"Yepes",
"P.",
""
],
[
"Zhalov",
"M.",
""
]
] |
0706.3357 | Michela Mapelli | M. Mapelli (1), E. Ripamonti (2) ((1) University of Z\"urich, (2)
Kapteyn Astronomical Institute, University of Groningen) | Primordial gas heating by dark matter and structure formation | 4 pages, 4 figures, to appear in the "Memorie della SAIt",
proceedings of the "LI congresso della Societa' Astronomica Italiana",
Firenze, April 17-20 2007 | Mem.Soc.Ast.It.75:282,2007 | null | null | astro-ph | null | Dark matter (DM) decays and annihilations might heat and partially reionize
the Universe at high redshift. Although this effect is not important for the
cosmic reionization, the gas heating due to DM particles might affect the
structure formation. In particular, the critical halo mass for collapse is
increased up to a factor of ~2. Also the fraction of gas which collapses inside
the smallest halos is substantially reduced with respect to the cosmological
value. These effects imply that DM decays and annihilations might delay the
formation of the first structures and reduce the total star mass in the
smallest halos.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:40:31 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Mapelli",
"M.",
""
],
[
"Ripamonti",
"E.",
""
]
] |
0706.3358 | Victor Abramovsky | V.A. Abramovsky, N.V. Radchenko | KNO scaling in processes of electron-positron annihilation to hadrons | 11 pages, 5 figures | null | null | null | hep-ph | null | The charged particles multiplicity distribution in the KNO form is discussed
in processes of $e^+e^-$ annihilation at energies $\sqrt{s}$ 14 -- 206.2 GeV.
The experimental data are compared to data, obtained with Monte Carlo
simulation in PYTHIA in the Lund quark string model. It is shown, that both
experimental and simulated data are described by the same distribution function
in the KNO form. It is shown, that the KNO scaling is consequence of quark
string hadronization dynamics in the Lund string model.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:43:10 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Abramovsky",
"V. A.",
""
],
[
"Radchenko",
"N. V.",
""
]
] |
0706.3359 | Edward Witten | Edward Witten | Three-Dimensional Gravity Revisited | 82 pp | null | null | null | hep-th | null | We consider the problem of identifying the CFT's that may be dual to pure
gravity in three dimensions with negative cosmological constant. The c-theorem
indicates that three-dimensional pure gravity is consistent only at certain
values of the coupling constant, and the relation to Chern-Simons gauge theory
hints that these may be the values at which the dual CFT can be holomorphically
factorized. If so, and one takes at face value the minimum mass of a BTZ black
hole, then the energy spectrum of three-dimensional gravity with negative
cosmological constant can be determined exactly. At the most negative possible
value of the cosmological constant, the dual CFT is very likely the monster
theory of Frenkel, Lepowsky, and Meurman. The monster theory may be the first
in a discrete series of CFT's that are dual to three-dimensional gravity. The
partition function of the second theory in the sequence can be determined on a
hyperelliptic Riemann surface of any genus. We also make a similar analysis of
supergravity.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:45:04 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Witten",
"Edward",
""
]
] |
0706.3360 | Stefano Giorgini | Stefano Giorgini, Lev P. Pitaevskii, Sandro Stringari | Theory of ultracold Fermi gases | Revised and abridged version accepted for publication in Rev. Mod.
Phys.: 63 pages, 36 figures | null | 10.1103/RevModPhys.80.1215 | null | cond-mat.other | null | The physics of quantum degenerate Fermi gases in uniform as well as in
harmonically trapped configurations is reviewed from a theoretical perspective.
Emphasis is given to the effect of interactions which play a crucial role,
bringing the gas into a superfluid phase at low temperature. In these dilute
systems interactions are characterized by a single parameter, the s-wave
scattering length, whose value can be tuned using an external magnetic field
near a Feshbach resonance. The BCS limit of ordinary Fermi superfluidity, the
Bose-Einstein condensation (BEC) of dimers and the unitary limit of large
scattering length are important regimes exhibited by interacting Fermi gases.
In particular the BEC and the unitary regimes are characterized by a high value
of the superfluid critical temperature, of the order of the Fermi temperature.
Different physical properties are discussed, including the density profiles and
the energy of the ground-state configurations, the momentum distribution, the
fraction of condensed pairs, collective oscillations and pair breaking effects,
the expansion of the gas, the main thermodynamic properties, the behavior in
the presence of optical lattices and the signatures of superfluidity, such as
the existence of quantized vortices, the quenching of the moment of inertia and
the consequences of spin polarization. Various theoretical approaches are
considered, ranging from the mean-field description of the BCS-BEC crossover to
non-perturbative methods based on quantum Monte Carlo techniques. A major goal
of the review is to compare the theoretical predictions with the available
experimental results.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:02:52 GMT"
},
{
"version": "v2",
"created": "Mon, 14 Jan 2008 14:07:18 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Giorgini",
"Stefano",
""
],
[
"Pitaevskii",
"Lev P.",
""
],
[
"Stringari",
"Sandro",
""
]
] |
0706.3361 | Ricardo Carretero | H.E. Nistazakis, D.J. Frantzeskakis, P.G. Kevrekidis, B.A. Malomed, R.
Carretero-Gonzalez, and A.R. Bishop | Polarized States and Domain Walls in Spinor Bose-Einstein Condensates | 7 pages, 9 figures, submitted to Phys. Rev. A | Phys. Rev. A 76 (2007) 063603 | 10.1103/PhysRevA.76.063603 | null | cond-mat.other | null | We study spin-polarized states and their stability in anti-ferromagnetic
states of spinor (F=1) quasi-one-dimensional Bose-Einstein condensates. Using
analytical approximations and numerical methods, we find various types of
polarized states, including: patterns of the Thomas-Fermi type; structures with
a pulse-shape in one component inducing a hole in the other components; states
with holes in all three components; and domain walls. A Bogoliubov-de Gennes
analysis reveals that families of these states contain intervals of a weak
oscillatory instability, except for the domain walls, which are always stable.
The development of the instabilities is examined by means of direct numerical
simulations.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:46:08 GMT"
}
] | 2010-12-10T00:00:00 | [
[
"Nistazakis",
"H. E.",
""
],
[
"Frantzeskakis",
"D. J.",
""
],
[
"Kevrekidis",
"P. G.",
""
],
[
"Malomed",
"B. A.",
""
],
[
"Carretero-Gonzalez",
"R.",
""
],
[
"Bishop",
"A. R.",
""
]
] |
0706.3362 | Konstantinos Drakakis | Konstantinos Drakakis | Three experimental pearls in Costas arrays | null | null | null | null | math.CO math.NT | null | The results of 3 experiments in Costas arrays are presented, for which
theoretical explanation is still not available: the number of dots on the main
diagonal of exponential Welch arrays, the parity populations of Golomb arrays
generated in fields of characteristic 2, and the maximal cross-correlation
between pairs of Welch or Golomb arrays generated in fields of size equal to a
Sophie Germain prime.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:48:04 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Drakakis",
"Konstantinos",
""
]
] |
0706.3363 | Maja Vu\v{c}kovi\'c | M. Vu\v{c}kovi\'c, C. Aerts, R. {\O}stensen, G. Nelemans, H. Hu, C.S.
Jeffery, V.S. Dhillon and T.R. Marsh | The binary properties of the pulsating subdwarf B eclipsing binary PG
1336-018 (NY Vir) | accepted for publication in A&A, 12 pages, 10 figures, 3 tables | null | 10.1051/0004-6361:20077179 | null | astro-ph | null | We present an unbiased orbit solution and mass determination of the
components of the eclipsing binary NY Vir as a critical test for the formation
scenarios of subdwarf B stars. We obtained high-resolution time series VLT/UVES
spectra and high-speed multicolour VLT/ULTRACAM photometric observations of NY
Vir, a rapidly pulsating subdwarf B star in a short period eclipsing binary.
Combining the radial velocity curve obtained from the VLT/UVES spectra with the
VLT/ULTRACAM multicolour lightcurves, we determined numerical orbital solutions
for this eclipsing binary. Due to the large number of free parameters and their
strong correlations, no unique solution could be found, only families of
solutions. We present three solutions of equal statistical significance, two of
which are compatible with the primary having gone through a core He-flash and a
common-envelope phase described by the $\alpha$-formalism. These two models
have an sdB primary of 0.466 \msol and 0.389 \msol, respectively. Finally, we
report the detection of the Rossiter-McLaughlin effect for NY Vir.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:50:32 GMT"
}
] | 2016-08-14T00:00:00 | [
[
"Vučković",
"M.",
""
],
[
"Aerts",
"C.",
""
],
[
"Østensen",
"R.",
""
],
[
"Nelemans",
"G.",
""
],
[
"Hu",
"H.",
""
],
[
"Jeffery",
"C. S.",
""
],
[
"Dhillon",
"V. S.",
""
],
[
"Marsh",
"T. R.",
""
]
] |
0706.3364 | Jacob Bourjaily | Jacob L. Bourjaily | Unfolding Geometric Unification in M-Theory | 8 pages, 2 figures | null | null | null | hep-th | null | By reinterpreting the familiar tools and ideas of M-theory model building, we
show how a G2-manifold locally engineered to give rise to massless matter
representations of an SU(5) grand unified model can be smoothly unfolded into a
G2-manifold giving rise to SU(3)xSU(2) gauge theory with the corresponding
matter representations. These ideas could lead to new insights in string
phenomenology because much of the arbitrariness of M-theory model building can
be removed by supposing, for example, that the singularities giving rise to
Standard Model particles could arise from unfolding a more singular, grand
unified geometry.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:57:45 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Bourjaily",
"Jacob L.",
""
]
] |
0706.3365 | Sreenivasa Bondili N S | B. S. Nara Singh, A. N. Steer, D. G. Jenkins, R. Wadsworth, M. A.
Bentley, P. J. Davies, R. Glover, N. S. Pattabiraman, C. J. Lister, T. Grahn,
P. T. Greenlees, P. Jones, R. Julin, S. Juutinen, M. Leino, M. Nyman, J.
Pakarinen, P. Rahkila, J. Saren, C. Scholey, J. Sorri, J. Uusitalo, P. A.
Butler, M. Dimmock, D. T. Joss, J. Thomson, B. Cederwall, B. Hadinia, and M.
Sandzelius | Coulomb shifts and shape changes in the mass 70 region | 10 pages, 2 figures | null | 10.1103/PhysRevC.75.061301 | null | nucl-ex | null | The technique of recoil beta tagging has been developed which allows prompt
gamma decays in nuclei from excited states to be correlated with electrons from
their subsequent short-lived beta decay. This technique is ideal for studying
nuclei very far from stability and improves in sensitivity for very short-lived
decays and for high decay Q-values. The method has allowed excited states in
78Y to be observed for the first time, as well as an extension in the knowledge
of T=1 states in 74Rb. From this new information it has been possible to
compare Coulomb energy differences (CED) between T=1 states in 70Br/70Se,
74Rb/74Kr, and 78Y/78Sr. The A=70 CED exhibit an anomalous behavior which is
inconsistent with all other known CED. This behavior may be accounted for
qualitatively in terms of small variations in the Coulomb energy arising from
shape changes.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 15:56:32 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Singh",
"B. S. Nara",
""
],
[
"Steer",
"A. N.",
""
],
[
"Jenkins",
"D. G.",
""
],
[
"Wadsworth",
"R.",
""
],
[
"Bentley",
"M. A.",
""
],
[
"Davies",
"P. J.",
""
],
[
"Glover",
"R.",
""
],
[
"Pattabiraman",
"N. S.",
""
],
[
"Lister",
"C. J.",
""
],
[
"Grahn",
"T.",
""
],
[
"Greenlees",
"P. T.",
""
],
[
"Jones",
"P.",
""
],
[
"Julin",
"R.",
""
],
[
"Juutinen",
"S.",
""
],
[
"Leino",
"M.",
""
],
[
"Nyman",
"M.",
""
],
[
"Pakarinen",
"J.",
""
],
[
"Rahkila",
"P.",
""
],
[
"Saren",
"J.",
""
],
[
"Scholey",
"C.",
""
],
[
"Sorri",
"J.",
""
],
[
"Uusitalo",
"J.",
""
],
[
"Butler",
"P. A.",
""
],
[
"Dimmock",
"M.",
""
],
[
"Joss",
"D. T.",
""
],
[
"Thomson",
"J.",
""
],
[
"Cederwall",
"B.",
""
],
[
"Hadinia",
"B.",
""
],
[
"Sandzelius",
"M.",
""
]
] |
0706.3366 | Debabrata Panja | Debabrata Panja, Frank M. Selten | Extreme Associated Functions: Optimally Linking Local Extremes to
Large-scale Atmospheric Circulation Structures | 10 pages, 7 figures, 14 eps figure files; to appear in J. Atmos.
Chem. Phys | Atmos. Chem. Phys. Discuss. 7, 14433-14460 (2007) | 10.5194/acpd-7-14433-2007 | null | physics.ao-ph physics.geo-ph | null | We present a new statistical method to optimally link local weather extremes
to large-scale atmospheric circulation structures. The method is illustrated
using July-August daily mean temperature at 2m height (T2m) time-series over
the Netherlands and 500 hPa geopotential height (Z500) time-series over the
Euroatlantic region of the ECMWF reanalysis dataset (ERA40). The method
identifies patterns in the Z500 time-series that optimally describe, in a
precise mathematical sense, the relationship with local warm extremes in the
Netherlands. Two patterns are identified; the most important one corresponds to
a blocking high pressure system leading to subsidence and calm, dry and sunny
conditions over the Netherlands. The second one corresponds to a rare, easterly
flow regime bringing warm, dry air into the region. The patterns are robust;
they are also identified in shorter subsamples of the total dataset. The method
is generally applicable and might prove useful in evaluating the performance of
climate models in simulating local weather extremes.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 16:11:02 GMT"
},
{
"version": "v2",
"created": "Tue, 26 Jun 2007 15:27:31 GMT"
},
{
"version": "v3",
"created": "Tue, 25 Sep 2007 14:21:05 GMT"
}
] | 2020-11-04T00:00:00 | [
[
"Panja",
"Debabrata",
""
],
[
"Selten",
"Frank M.",
""
]
] |
0706.3367 | J. M. Maillard | S. Boukraa, S. Hassani, J.-M. Maillard, N. Zenine | Singularities of $n$-fold integrals of the Ising class and the theory of
elliptic curves | 39 pages, 7 figures | null | 10.1088/1751-8113/40/39/003 | null | math-ph cond-mat.stat-mech hep-th math.MP physics.comp-ph | null | We introduce some multiple integrals that are expected to have the same
singularities as the singularities of the $ n$-particle contributions
$\chi^{(n)}$ to the susceptibility of the square lattice Ising model. We find
the Fuchsian linear differential equation satisfied by these multiple integrals
for $ n=1, 2, 3, 4$ and only modulo some primes for $ n=5$ and $ 6$, thus
providing a large set of (possible) new singularities of the $\chi^{(n)}$. We
discuss the singularity structure for these multiple integrals by solving the
Landau conditions. We find that the singularities of the associated ODEs
identify (up to $n= 6$) with the leading pinch Landau singularities. The second
remarkable obtained feature is that the singularities of the ODEs associated
with the multiple integrals reduce to the singularities of the ODEs associated
with a {\em finite number of one dimensional integrals}. Among the
singularities found, we underline the fact that the quadratic polynomial
condition $ 1+3 w +4 w^2 = 0$, that occurs in the linear differential equation
of $ \chi^{(3)}$, actually corresponds to a remarkable property of selected
elliptic curves, namely the occurrence of complex multiplication. The
interpretation of complex multiplication for elliptic curves as complex fixed
points of the selected generators of the renormalization group, namely
isogenies of elliptic curves, is sketched. Most of the other singularities
occurring in our multiple integrals are not related to complex multiplication
situations, suggesting an interpretation in terms of (motivic) mathematical
structures beyond the theory of elliptic curves.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 16:05:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Boukraa",
"S.",
""
],
[
"Hassani",
"S.",
""
],
[
"Maillard",
"J. -M.",
""
],
[
"Zenine",
"N.",
""
]
] |
0706.3368 | Amaya Moro-Martin | Amaya Moro-Martin, Renu Malhotra, John M. Carpenter, Lynne A.
Hillenbrand, Sebastian Wolf, Michael R. Meyer, David Hollenbach, Joan Najita,
Thomas Henning | The dust, planetesimals and planets of HD 38529 | 23 pages, including 1 table and 5 figures. Accepted for publication
in ApJ | null | 10.1086/521093 | null | astro-ph | null | HD 38529 is a post-main sequence G8III/IV star (3.5 Gyr old) with a planetary
system consisting of at least two planets having Msin(i) of 0.8 MJup and 12.2
MJup, semimajor axes of 0.13 AU and 3.74 AU, and eccentricities of 0.25 and
0.35, respectively. Spitzer observations show that HD 38529 has an excess
emission above the stellar photosphere, with a signal-to-noise ratio (S/N) at
70 micron of 4.7, a small excess at 33 micron (S/N=2.6) and no excess <30
micron. We discuss the distribution of the potential dust-producing
planetesimals from the study of the dynamical perturbations of the two known
planets, considering in particular the effect of secular resonances. We
identify three dynamically stable niches at 0.4-0.8 AU, 20-50 AU and beyond 60
AU. We model the spectral energy distribution of HD 38529 to find out which of
these niches show signs of harboring dust-producing plantesimals. The secular
analysis, together with the SED modeling resuls, suggest that the planetesimals
responsible for most of the dust emission are likely located within 20-50 AU, a
configuration that resembles that of the Jovian planets + Kuiper Belt in our
Solar System. Finally, we place upper limits (8E-6 lunar masses of 10 micron
particles) to the amount of dust that could be located in the dynamically
stable region that exists between the two planets (0.25--0.75 AU).
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 16:12:30 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Moro-Martin",
"Amaya",
""
],
[
"Malhotra",
"Renu",
""
],
[
"Carpenter",
"John M.",
""
],
[
"Hillenbrand",
"Lynne A.",
""
],
[
"Wolf",
"Sebastian",
""
],
[
"Meyer",
"Michael R.",
""
],
[
"Hollenbach",
"David",
""
],
[
"Najita",
"Joan",
""
],
[
"Henning",
"Thomas",
""
]
] |
0706.3369 | Laurent Saminadayar | L. Saminadayar, C. B\"auerle and D. Mailly | Equilibrium properties of mesoscopic quantum conductors | 21 pages, 19 figures | Encyclopedia of Nanoscience and Nanotechnology, Vol. 3, p. 267-285
(2004) | null | null | cond-mat.mes-hall | null | Review article on equilibrium properties of mesoscopic quantum conductors.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 16:15:33 GMT"
},
{
"version": "v2",
"created": "Thu, 5 Jul 2007 08:47:30 GMT"
}
] | 2007-07-05T00:00:00 | [
[
"Saminadayar",
"L.",
""
],
[
"Bäuerle",
"C.",
""
],
[
"Mailly",
"D.",
""
]
] |
0706.3370 | Gerald Teschl | F. Gesztesy, H. Holden, J. Michor, and G. Teschl | The algebro-geometric initial value problem for the Ablowitz-Ladik
hierarchy | 47 pages | Discrete Contin. Dyn. Syst. 26:1, 151-196 (2010) | 10.3934/dcds.2009.26.151 | null | nlin.SI math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the algebro-geometric initial value problem for the Ablowitz-Ladik
hierarchy with complex-valued initial data and prove unique solvability
globally in time for a set of initial (Dirichlet divisor) data of full measure.
To this effect we develop a new algorithm for constructing stationary
complex-valued algebro-geometric solutions of the Ablowitz-Ladik hierarchy,
which is of independent interest as it solves the inverse algebro-geometric
spectral problem for general (non-unitary) Ablowitz-Ladik Lax operators,
starting from a suitably chosen set of initial divisors of full measure.
Combined with an appropriate first-order system of differential equations with
respect to time (a substitute for the well-known Dubrovin-type equations), this
yields the construction of global algebro-geometric solutions of the
time-dependent Ablowitz-Ladik hierarchy.
The treatment of general (non-unitary) Lax operators associated with general
coefficients for the Ablowitz-Ladik hierarchy poses a variety of difficulties
that, to the best of our knowledge, are successfully overcome here for the
first time. Our approach is not confined to the Ablowitz-Ladik hierarchy but
applies generally to (1+1)-dimensional completely integrable soliton equations
of differential-difference type.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 16:17:27 GMT"
},
{
"version": "v2",
"created": "Tue, 15 Jan 2008 09:20:23 GMT"
},
{
"version": "v3",
"created": "Thu, 15 Oct 2009 15:02:17 GMT"
}
] | 2009-10-15T00:00:00 | [
[
"Gesztesy",
"F.",
""
],
[
"Holden",
"H.",
""
],
[
"Michor",
"J.",
""
],
[
"Teschl",
"G.",
""
]
] |
0706.3371 | Roberto De Renzi | M. Bimbi, G. Allodi, R. De Renzi, C. Mazzoli, H. Berger | Muon Spin Spectroscopy evidence of the violation of Anderson condition
in magnetite | 4 pages, 5 figures, Additional material EPAPS.pdf (2 pages, 2
figure), submitted to Phys. Rev. Lett | null | 10.1103/PhysRevB.77.045115 | null | cond-mat.str-el | null | We present new muon spectroscopy data on a Fe$_3$O$_4$ single crystal,
revealing different spin precession patterns in five distinct temperature
ranges. A careful analysis of the local field and its straightforward modeling
obtains surprisingly good agreement with experiments only if a very specific
model of localized charges violating Anderson condition, and a correlated muon
local dynamics are implemented. Muon evidence for fluctuations just above the
Verwey temperature, precursor of the low temperature charge localized state, is
provided.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 16:17:29 GMT"
}
] | 2013-05-29T00:00:00 | [
[
"Bimbi",
"M.",
""
],
[
"Allodi",
"G.",
""
],
[
"De Renzi",
"R.",
""
],
[
"Mazzoli",
"C.",
""
],
[
"Berger",
"H.",
""
]
] |
0706.3372 | Vinko Zlati\'c | Gorka Zamora--L\'opez, Vinko Zlati\'c, Changsong Zhou, Hrvoje
\v{S}tefan\v{c}i\'c, J\"urgen Kurths | Reciprocity of Networks with Degree Correlations and Arbitrary Degree
Sequences | 8 pages, 3 figures, added a new table and a new figure, accepted for
publication in Phys.Rev.E | null | 10.1103/PhysRevE.77.016106 | null | cond-mat.stat-mech cond-mat.dis-nn | null | Although most of the real networks contain a mixture of directed and
bidirectional (reciprocal) connections, the reciprocity $r$ has received little
attention as a subject of theoretical understanding. We study the expected
reciprocity of networks with an arbitrary degree sequence and a broad class of
degree correlations by means of statistical ensemble approach. We demonstrate
that degree correlations are crucial to understand the reciprocity in real
networks and a hierarchy of correlation contributions to $r$ is revealed.
Numerical experiments using novel network randomization methods show very good
agreement to our analytical estimations.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 16:31:00 GMT"
},
{
"version": "v2",
"created": "Wed, 14 Nov 2007 13:07:30 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Zamora--López",
"Gorka",
""
],
[
"Zlatić",
"Vinko",
""
],
[
"Zhou",
"Changsong",
""
],
[
"Štefančić",
"Hrvoje",
""
],
[
"Kurths",
"Jürgen",
""
]
] |
0706.3373 | Gabriel Cardoso | Gabriel Lopes Cardoso, Anna Ceresole, Gianguido Dall'Agata, Johannes
M. Oberreuter, Jan Perz | First-order flow equations for extremal black holes in very special
geometry | 21 pages. v2: Summary section added | JHEP 0710:063,2007 | 10.1088/1126-6708/2007/10/063 | DFPD-07TH10, LMU-ASC 38/07, MPP-2007-73 | hep-th | null | We construct interpolating solutions describing single-center static extremal
non-supersymmetric black holes in four-dimensional N=2 supergravity theories
with cubic prepotentials. To this end, we derive and solve first-order flow
equations for rotating electrically charged extremal black holes in a Taub-NUT
geometry in five dimensions. We then use the connection between five- and
four-dimensional extremal black holes to obtain four-dimensional flow equations
and we give the corresponding solutions.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 16:22:14 GMT"
},
{
"version": "v2",
"created": "Sun, 30 Sep 2007 09:05:50 GMT"
}
] | 2009-11-18T00:00:00 | [
[
"Cardoso",
"Gabriel Lopes",
""
],
[
"Ceresole",
"Anna",
""
],
[
"Dall'Agata",
"Gianguido",
""
],
[
"Oberreuter",
"Johannes M.",
""
],
[
"Perz",
"Jan",
""
]
] |
0706.3374 | David Leibrandt | David R. Leibrandt, Robert J. Clark, Jaroslaw Labaziewicz, Paul
Antohi, Waseem Bakr, Kenneth R. Brown, and Isaac L. Chuang | Laser ablation loading of a surface-electrode ion trap | 4 pages, 4 figures | null | 10.1103/PhysRevA.76.055403 | null | quant-ph | null | We demonstrate loading by laser ablation of $^{88}$Sr$^+$ ions into a
mm-scale surface-electrode ion trap. The laser used for ablation is a pulsed,
frequency-tripled Nd:YAG with pulse energies of 1-10 mJ and durations of 3-5
ns. An additional laser is not required to photoionize the ablated material.
The efficiency and lifetime of several candidate materials for the laser
ablation target are characterized by measuring the trapped ion fluorescence
signal for a number of consecutive loads. Additionally, laser ablation is used
to load traps with a trap depth (40 meV) below where electron impact ionization
loading is typically successful ($\gtrsim$ 500 meV).
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 16:23:01 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Leibrandt",
"David R.",
""
],
[
"Clark",
"Robert J.",
""
],
[
"Labaziewicz",
"Jaroslaw",
""
],
[
"Antohi",
"Paul",
""
],
[
"Bakr",
"Waseem",
""
],
[
"Brown",
"Kenneth R.",
""
],
[
"Chuang",
"Isaac L.",
""
]
] |
0706.3375 | Carsten Allefeld | Carsten Allefeld, Markus M\"uller, J\"urgen Kurths | Eigenvalue Decomposition as a Generalized Synchronization Cluster
Analysis | Submitted Oct 2005, accepted Jan 2006, "published" Oct 2007, actually
available Jan 2008 | International Journal of Bifurcation and Chaos, 17(10):
3493--3497, 2007 | 10.1142/S0218127407019251 | null | physics.data-an | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by the recent demonstration of its use as a tool for the detection
and characterization of phase-shape correlations in multivariate time series,
we show that eigenvalue decomposition can also be applied to a matrix of
indices of bivariate phase synchronization strength. The resulting method is
able to identify clusters of synchronized oscillators, and to quantify their
strength as well as the degree of involvement of an oscillator in a cluster.
Since for the case of a single cluster the method gives similar results as our
previous approach, it can be seen as a generalized Synchronization Cluster
Analysis, extending its field of application to more complex situations. The
performance of the method is tested by applying it to simulation data.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 16:23:29 GMT"
},
{
"version": "v2",
"created": "Thu, 17 Jan 2008 16:20:58 GMT"
},
{
"version": "v3",
"created": "Wed, 3 Sep 2008 18:02:57 GMT"
}
] | 2008-09-03T00:00:00 | [
[
"Allefeld",
"Carsten",
""
],
[
"Müller",
"Markus",
""
],
[
"Kurths",
"Jürgen",
""
]
] |
0706.3376 | Ana Maria Rey | A. M. Rey, L. Jiang and M. D. Lukin | Quantum limited measurements of atomic scattering properties | 7 pages, 5 figures. References added | null | 10.1103/PhysRevA.76.053617 | null | cond-mat.other | null | We propose a method to perform precision measurements of the interaction
parameters in systems of N ultra-cold spin 1/2 atoms. The spectroscopy is
realized by first creating a coherent spin superposition of the two relevant
internal states of each atom and then letting the atoms evolve under a
squeezing Hamiltonian. The non-linear nature of the Hamiltonian decreases the
fundamental limit imposed by the Heisenberg uncertainty principle to N^(-2), a
factor of N smaller than the fundamental limit achievable with non-interacting
atoms. We study the effect of decoherence and show that even with decoherence,
entangled states can outperform the signal to noise limit of non-entangled
states. We present two possible experimental implementations of the method
using Bose-Einstein spinor condensates and fermionic atoms loaded in optical
lattices and discuss their advantages and disadvantages.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 16:40:12 GMT"
},
{
"version": "v2",
"created": "Fri, 3 Aug 2007 14:58:54 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Rey",
"A. M.",
""
],
[
"Jiang",
"L.",
""
],
[
"Lukin",
"M. D.",
""
]
] |
0706.3377 | Julia Slutsker | Julia Slutsker, Andrei Artemev and Alexander L. Roytburd | Domain Structures in Confined Nanoferroelectrics: Phase Field Approach | 13 pages, 6 figures | null | null | null | cond-mat.mtrl-sci | null | Phase field modeling of domain structures in ferroelectrics nanorods of
different shape and sizes is presented. The vortex domain configurations in
confined ferroelectrics have been explored by varying the ratio of the energies
of electrostatic and elastic interactions. It is shown that a strong effect of
the electrostatic interactions can cause the formation of 90o domain walls that
do not satisfy the condition of strain compatibility. A good agreement between
the results of phase field modeling and the results of atomistic calculations
for nano ferroelectrics demonstrates that the phase field approach provides an
effective tool for the analysis of domain structures in nano-ferroelectrics.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 17:02:41 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Slutsker",
"Julia",
""
],
[
"Artemev",
"Andrei",
""
],
[
"Roytburd",
"Alexander L.",
""
]
] |
0706.3378 | Ana Maria Rey | A. M. Rey, L. Jiang, M. Fleischhauer, E. Demler and M.D. Lukin | Many-body protected entanglement generation in interacting spin systems | 11 pages, 7 figures. This paper is a longer version of the paper
cond-mat/0703108 | null | 10.1103/PhysRevA.77.052305 | null | cond-mat.other | null | We discuss a method to achieve decoherence resistent entanglement generation
in two level spin systems governed by gapped and multi-degenerate Hamiltonians.
In such systems, while the large number of degrees of freedom in the ground
state levels allows to create various quantum superpositions, the energy gap
prevents decoherence. We apply the protected evolution to achieve decoherence
resistent generation of many particle GHZ states and show it can significantly
increase the sensitivity in frequency spectroscopy. We discuss how to engineer
the desired many-body protected manifold in two specific physical systems,
trapped ions and neutral atoms in optical lattices, and present simple
expressions for the fidelity of GHZ generation under non-ideal conditions.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 17:13:16 GMT"
},
{
"version": "v2",
"created": "Fri, 4 Jan 2008 22:34:28 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Rey",
"A. M.",
""
],
[
"Jiang",
"L.",
""
],
[
"Fleischhauer",
"M.",
""
],
[
"Demler",
"E.",
""
],
[
"Lukin",
"M. D.",
""
]
] |
0706.3379 | Dirk Vertigan | Dirk Vertigan (Department of Mathematics, Louisiana State University) | Self-Replicating Space-Cells and the Cosmological Constant | 15 pages, no figures, LaTeX | null | null | null | gr-qc nlin.AO | null | We consider what the implications would be if there were a discrete
fundamental model of physics based on locally-finite self-interacting
information, in which there is no presumption of the familiar space and laws of
physics, but from which such space and laws can nevertheless be shown to be
able to emerge stably from such a fundamental model. We argue that if there is
such a model, then the familiar laws of physics, including Standard Model
constants, etc., must be encodable by a finite quantity C, called the
complexity, of self-interacting information I, called a Space-Cell. Copies of
Space-Cell I must be distributed throughout space, at a roughly constant and
near-Planck density, and copies must be created or destroyed as space expands
or contracts. We then argue that each Space-Cell is a self-replicator that can
duplicate in times ranging from as fast as near-Planck-times to as slow as
Cosmological-Constant-time which is 10^{61} Planck-times. From standard
considerations of computation, we argue this slowest duplication rate just
requires that 10^{61} is less than about 2^C, the number of length-C binary
strings, hence requiring only the modest complexity C at least 203, and at most
a few thousand. We claim this provides a reasonable explanation for a
dimensionless constant being as large as 10^{61}, and hence for the
Cosmological Constant being a tiny positive 10^{-122}. We also discuss a
separate conjecture on entropy flow in Hole-Bang Transitions. We then present
Cosmological Natural Selection II.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 17:22:23 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Vertigan",
"Dirk",
"",
"Department of Mathematics, Louisiana State University"
]
] |
0706.3380 | Lucas Wagner | Lucas K. Wagner | Transition metal oxides using quantum Monte Carlo | 20 pages, 4 figures, to appear as a topical review in J. Physics:
Condensed Matter | null | 10.1088/0953-8984/19/34/343201 | null | cond-mat.str-el cond-mat.mtrl-sci | null | The transition metal-oxygen bond appears prominently throughout chemistry and
solid-state physics. Many materials, from biomolecules to ferroelectrics to the
components of supernova remnants contain this bond in some form. Many of these
materials' properties strongly depend on fine details of the TM-O bond and
intricate correlation effects, which make accurate calculations of their
properties very challenging. We present quantum Monte Carlo, an explicitly
correlated class of methods, to improve the accuracy of electronic structure
calculations over more traditional methods like density functional theory. We
find that unlike s-p type bonding, the amount of hybridization of the d-p bond
in TM-O materials is strongly dependant on electronic correlation.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 17:42:06 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Wagner",
"Lucas K.",
""
]
] |
0706.3381 | Francesc Planas-Vilanova | Jos\'e M. Giral, Francesc Planas-Vilanova | Integral degree of a ring and reduction numbers | 18 pages | null | null | null | math.AC | null | The supremum of reduction numbers of ideals having principal reductions is
expressed in terms of the integral degree, a new invariant of the ring, which
is finite provided the ring has finite integral closure. As a consequence, one
obtains bounds for the Castelnuovo-Mumford regularity of the Rees algebra and
for the Artin-Rees numbers.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 17:39:15 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Giral",
"José M.",
""
],
[
"Planas-Vilanova",
"Francesc",
""
]
] |
0706.3382 | Richard Szabo | Henry C.D. Cove, Zoltan Kadar and Richard J. Szabo | DLCQ Strings, Twist Fields and One-Loop Correlators on a Permutation
Orbifold | 48 pages, 1 figure; v2: typos corrected | Nucl.Phys.B793:260-306,2008 | 10.1016/j.nuclphysb.2007.10.014 | HWM-07-17, EMPG-07-13 | hep-th | null | We investigate some aspects of the relationship between matrix string theory
and light-cone string field theory by analysing the correspondence between the
two-loop thermal partition function of DLCQ strings in flat space and the
integrated two-point correlator of twist fields in a symmetric product orbifold
conformal field theory at one-loop order. This is carried out by deriving
combinatorial expressions for generic twist field correlation functions in
permutation orbifolds using the covering surface method, by deriving the
one-loop modification of the twist field interaction vertex, and by relating
the two-loop finite temperature DLCQ string theory to the theory of Prym
varieties for genus two covers of an elliptic curve. The case of bosonic Z(2)
orbifolds is worked out explicitly and precise agreement between both
amplitudes is found. We use these techniques to derive explicit expressions for
Z(2) orbifold spin twist field correlation functions in the Type II and
heterotic string theories.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 17:47:19 GMT"
},
{
"version": "v2",
"created": "Tue, 17 Jul 2007 08:33:22 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Cove",
"Henry C. D.",
""
],
[
"Kadar",
"Zoltan",
""
],
[
"Szabo",
"Richard J.",
""
]
] |
0706.3383 | Leticia Cunqueiro | L.Cunqueiro, J.Dias de Deus, E.G.Ferreiro and C.Pajares | Universal behavior of baryons and mesons' transverse momentum
distributions in the framework of percolation of strings | Presented at "Heavy Ion Collisions at the LHC: last call for
predictions", Geneva Switzerland, May 14th-June 8th | null | null | null | hep-ph | null | In the framework of percolation of strings, we present predictions for the
$R_{AA}$ and $R_{CP}$ for mesons and baryons and for $\bar{p}/\pi^{0}$ ratios
at LHC energies.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 17:52:50 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Cunqueiro",
"L.",
""
],
[
"de Deus",
"J. Dias",
""
],
[
"Ferreiro",
"E. G.",
""
],
[
"Pajares",
"C.",
""
]
] |
0706.3384 | Olalla Castro Alvaredo | J.L. Cardy, O.A. Castro-Alvaredo and B. Doyon | Form factors of branch-point twist fields in quantum integrable models
and entanglement entropy | 40 pages, 10 eps figures | J. Stat. Phys.130:129-168, 2008 | 10.1007/s10955-007-9422-x | null | hep-th quant-ph | null | In this paper we compute the leading correction to the bipartite entanglement
entropy at large sub-system size, in integrable quantum field theories with
diagonal scattering matrices. We find a remarkably universal result, depending
only on the particle spectrum of the theory and not on the details of the
scattering matrix. We employ the "replica trick" whereby the entropy is
obtained as the derivative with respect to n of the trace of the n-th power of
the reduced density matrix of the sub-system, evaluated at n=1. The main
novelty of our work is the introduction of a particular type of twist fields in
quantum field theory that are naturally related to branch points in an
n-sheeted Riemann surface. Their two-point function directly gives the scaling
limit of the trace of the n-th power of the reduced density matrix. Taking
advantage of integrability, we use the expansion of this two-point function in
terms of form factors of the twist fields, in order to evaluate it at large
distances in the two-particle approximation. Although this is a well-known
technique, the new geometry of the problem implies a modification of the form
factor equations satisfied by standard local fields of integrable quantum field
theory. We derive the new form factor equations and provide solutions, which we
specialize both to the Ising and sinh-Gordon models.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 18:30:38 GMT"
},
{
"version": "v2",
"created": "Tue, 16 Oct 2007 17:55:34 GMT"
}
] | 2011-01-27T00:00:00 | [
[
"Cardy",
"J. L.",
""
],
[
"Castro-Alvaredo",
"O. A.",
""
],
[
"Doyon",
"B.",
""
]
] |
0706.3385 | Mario Centelles | S.K. Samaddar, J.N. De, X. Vinas, M. Centelles | Excitation energy dependence of symmetry energy of finite nuclei | 11 pages, 3 figures, revtex4; minor changes in text, axis label in
figure 1 corrected | Phys.Rev.C76:041602,2007 | 10.1103/PhysRevC.76.041602 | null | nucl-th | null | A finite range density and momentum dependent effective interaction is used
to calculate the density and temperature dependence of the symmetry energy
coefficient Csym(rho,T) of infinite nuclear matter. This symmetry energy is
then used in the local density approximation to evaluate the excitation energy
dependence of the symmetry energy coefficient of finite nuclei in a
microcanonical formulation that accounts for thermal and expansion effects. The
results are in good harmony with the recently reported experimental data from
energetic nucleus-nucleus collisions.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 18:16:01 GMT"
},
{
"version": "v2",
"created": "Thu, 11 Oct 2007 17:23:51 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Samaddar",
"S. K.",
""
],
[
"De",
"J. N.",
""
],
[
"Vinas",
"X.",
""
],
[
"Centelles",
"M.",
""
]
] |
0706.3386 | Eric Hilton | Eric J. Hilton, Paula Szkody, Anjum Mukadam (University of
Washington), Koji Mukai (NASA GSFC), Coel Hellier, Liza van Zyl (Keele
University), Lee Homer (Liverpool CC) | XMM-Newton Observations of the Cataclysmic Variable GW Lib | 16 pages, 4 figures; accepted for publication in AJ | Astron.J.134:1503-1507,2007 | 10.1086/521343 | null | astro-ph | null | XMM-Newton observations of the accreting, pulsating white dwarf in the
quiescent dwarf nova GW Librae were conducted to determine if the non-radial
pulsations present in previous UV and optical data affect the X-ray emission.
The non-radial pulsations are evident in the simultaneous Optical Monitor data
but are not detected in X-ray with an upper limit on the pulsation amplitude of
0.092 mags. The best fits to the X-ray spectrum are with a low temperature
diffuse gas model or a multi-temperature cooling flow model, with a strong
OVIII line, similar to other short period dwarf novae, but with a lower
temperature range than evident in normal short period dwarf novae. The lack of
pulsations and the spectrum likely indicate that the boundary layer does not
extend to the surface of the white dwarf.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 18:22:09 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hilton",
"Eric J.",
"",
"University of\n Washington"
],
[
"Szkody",
"Paula",
"",
"University of\n Washington"
],
[
"Mukadam",
"Anjum",
"",
"University of\n Washington"
],
[
"Mukai",
"Koji",
"",
"NASA GSFC"
],
[
"Hellier",
"Coel",
"",
"Keele\n University"
],
[
"van Zyl",
"Liza",
"",
"Keele\n University"
],
[
"Homer",
"Lee",
"",
"Liverpool CC"
]
] |
0706.3387 | Igor Komarov | Igor Komarov | Vadim Kuznetsov. Informal Biography by Eyes of His First Adviser | This is a contribution to the Vadim Kuznetsov Memorial Issue on
Integrable Systems and Related Topics, published in SIGMA (Symmetry,
Integrability and Geometry: Methods and Applications) at
http://www.emis.de/journals/SIGMA/ | SIGMA 3 (2007), 074, 6 pages | 10.3842/SIGMA.2007.074 | null | nlin.SI math-ph math.CA math.MP | null | The paper is dedicated to the memory of prominent theoretical physicist and
mathematician Dr. Vadim Kuznetsov who worked, in particular, in the fields of
the nonlinear dynamics, separation of variables, integrability theory, special
functions. It includes his short research biography, an account of the start of
his research career and the list of publications.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 18:24:16 GMT"
}
] | 2008-04-24T00:00:00 | [
[
"Komarov",
"Igor",
""
]
] |
0706.3388 | Mariano Quiros | Germano Nardini, Mariano Quiros, Andrea Wulzer | A Confining Strong First-Order Electroweak Phase Transition | 34 pages, 7 figures; v2: Reference added; v3: Version to appear in
JHEP | JHEP0709:077,2007 | 10.1088/1126-6708/2007/09/077 | UAB-FT-632 | hep-ph hep-th | null | In the Randall-Sundrum model where the radion is stabilized by a
Goldberger-Wise (GW) potential there is a supercooled transition from a
deconfined to a confined phase at temperatures orders of magnitude below the
typical Standard Model critical temperature. When the Higgs is localized at the
IR brane the electroweak phase transition is delayed and becomes a strong
first-order one where the Universe expands by a few e-folds. This generates the
possibility of having the out-of-equilibrium condition required by electroweak
baryogenesis in the electroweak phase transition. We have studied numerically
the region of the GW parameter space where the theory is consistent and the
latter possibility is realized. We have found that in most of the parameter
space the nucleation temperature is so low that sphalerons are totally inactive
inside the bubbles. The condition for sphalerons to be inactive after reheating
imposes an upper bound on the reheating temperature that is weaker for heavy
Higgs bosons so that the out-of-equilibrium condition seems to favor heavy over
light Higgses. The condition for sphalerons to be active outside the bubbles
puts an upper bound on the number of e-folds at the phase transition, roughly
consistent with the critical value required by low-scale inflation to solve the
cosmological horizon problem.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 18:44:16 GMT"
},
{
"version": "v2",
"created": "Mon, 9 Jul 2007 12:40:00 GMT"
},
{
"version": "v3",
"created": "Thu, 20 Sep 2007 16:33:56 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Nardini",
"Germano",
""
],
[
"Quiros",
"Mariano",
""
],
[
"Wulzer",
"Andrea",
""
]
] |
0706.3389 | Bruce Kleiner | Jeff Cheeger and Bruce Kleiner | Characterization of the Radon-Nikodym Property in terms of inverse
limits | null | null | null | null | math.FA math.MG | null | We clarify the relation between inverse systems, the Radon-Nikodym property,
the Asymptotic Norming Property of James-Ho, and the GFDA spaces introduced in
our earlier paper on differentiability of Lipschitz maps into Banach spaces.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 18:50:33 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Jun 2007 22:09:08 GMT"
},
{
"version": "v3",
"created": "Fri, 11 Jan 2008 21:30:11 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Cheeger",
"Jeff",
""
],
[
"Kleiner",
"Bruce",
""
]
] |
0706.3390 | Stephan Ulrich | Stephan Ulrich, Matthias Schr\"oter and Harry L. Swinney | Influence of friction on granular segregation | 3 pages, 2 figures | Phys. Rev. E 76, 042301 (2007) | 10.1103/PhysRevE.76.042301 | null | cond-mat.dis-nn cond-mat.soft | null | Vertical shaking of a mixture of small and large beads can lead to
segregation where the large beads either accumulate at the top of the sample,
the so called Brazil Nut effect (BNE), or at the bottom, the Reverse Brazil Nut
effect (RBNE). Here we demonstrate experimentally a sharp transition from the
RBNE to the BNE when the particle coefficient of friction increases due to
aging of the particles. This result can be explained by the two competing
mechanisms of buoyancy and sidewall-driven convection, where the latter is
assumed to grow in strength with increasing friction.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 18:51:42 GMT"
},
{
"version": "v2",
"created": "Sun, 13 Jan 2008 20:40:24 GMT"
}
] | 2008-01-13T00:00:00 | [
[
"Ulrich",
"Stephan",
""
],
[
"Schröter",
"Matthias",
""
],
[
"Swinney",
"Harry L.",
""
]
] |
0706.3391 | Brian Yanny | Heidi Jo Newberg, Brian Yanny, Nate Cole, Timothy C. Beers, Paola Re
Fiorentin, Donald P. Schneider, Ron Wilhelm | The Overdensity in Virgo, Sagittarius Debris, and the Asymmetric
Spheroid | 10 figures, ApJ in press | Astrophys.J.668:221-235,2007 | 10.1086/521068 | null | astro-ph | null | We investigate the relationship between several previously identified
Galactic halo stellar structures in the direction of Virgo using imaging and
spectroscopic observations of F turnoff stars and blue horizontal branch stars
from the Sloan Digital Sky Survey (SDSS) and the Sloan Extension for Galactic
Understanding and Exploration (SEGUE). We show that the Sagittarius dwarf
leading tidal tail does not pass through the solar neighborhood; it misses the
Sun by more than 15 kpc, passing through the Galactic plane outside the Solar
Circle. It also is not spatially coincident with the large stellar overdensity
S297+63-20.5 in the Virgo constellation. S297+63-20.5 has a distinct turnoff
color and kinematics. Faint (g ~ 20.3) turnoff stars in S297+63-20.5 have
line-of-sight, Galactic standard of rest velocities V(GSR)= 130 +/- 10 km/s,
opposite in sign to infalling Sgr tail stars. The path of the Sgr leading tidal
tail is also inconsistent with the positions of some of the nearer stars with
which it has been associated, and whose velocities have favored models with
prolate Milky Way potentials. We additionally show that the number densities of
brighter (g ~ 19.8) F turnoff stars are not symmetric about the Galactic
center, and that this discrepancy is not primarily due to the S297+63-20.5
moving group. Either the spheroid is asymmetric about the Galactic center, or
there are additional substructures that conspire to be on the same side of the
Galaxy as S297+63-20.5. The S297+63-20.5 overdensity in Virgo is likely
associated with two other previously identified Virgo substructures: the Virgo
Stellar Stream (VSS) and the Virgo Overdensity (VOD). However, the velocity
difference between the VSS and S297+63-20.5 and the difference in distance
estimates between the VOD and S297+63-20.5 must be reconciled.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 19:06:23 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Newberg",
"Heidi Jo",
""
],
[
"Yanny",
"Brian",
""
],
[
"Cole",
"Nate",
""
],
[
"Beers",
"Timothy C.",
""
],
[
"Fiorentin",
"Paola Re",
""
],
[
"Schneider",
"Donald P.",
""
],
[
"Wilhelm",
"Ron",
""
]
] |
0706.3392 | Sergey V. Lototsky | S. V. Lototsky and K. Stemmann | Solving SPDEs driven by colored noise: a chaos approach | null | null | null | null | math.PR math.AP | null | An Ito-Skorokhod bi-linear equation driven by infinitely many independent
colored noises is considered in a normal triple of Hilbert spaces. The special
feature of the equation is the appearance of the Wick product in the definition
of the Ito-Skorokhod integral, requiring innovative approaches to computing the
solution. A chaos expansion of the solution is derived and several truncations
of this expansion are studied. A recursive approximation of the solution is
suggested and the corresponding approximation error bound is computed.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 19:13:02 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Lototsky",
"S. V.",
""
],
[
"Stemmann",
"K.",
""
]
] |
0706.3393 | Alexey Koshelev | Alexey S. Koshelev and Theodore N. Tomaras | Towards a covariant model for cosmic self-acceleration | 10 pages, no figures; v2: version published in JHEP | JHEP0710:012,2007 | 10.1088/1126-6708/2007/10/012 | null | hep-th astro-ph hep-ph | null | An explicitly covariant formulation is presented of a modified DGP scenario
proposed recently [1], to avoid the instability of the self-accelerating
branch. It is based on the introduction of a bulk scalar field with appropriate
non-minimal coupling to the bulk Einstein-Hilbert term. The method is general
and may be applied to other models as well.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 19:33:34 GMT"
},
{
"version": "v2",
"created": "Tue, 9 Oct 2007 09:34:54 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Koshelev",
"Alexey S.",
""
],
[
"Tomaras",
"Theodore N.",
""
]
] |
0706.3394 | Eric Gimon | Eric G. Gimon and Thomas S. Levi | Black Ring Deconstruction | 10 pages, 2 figures | JHEP0804:098,2008 | 10.1088/1126-6708/2008/04/098 | null | hep-th | null | We present a sample microstate for a black ring in four and five dimensional
language. The microstate consists of a black string microstate with an
additional D6-brane. We show that with an appropriate choice of parameters the
piece involving the black string microstate falls down a long AdS throat, whose
M-theory lift is AdS_3 X S^2. We wrap a spinning dipole M2-brane on the S^2 in
the probe approximation. In IIA, this corresponds to a dielectric D2-brane
carrying only D0-charge. We conjecture this is the first approximation to a
cloud of D0-branes blowing up due to their non-abelian degrees of freedom and
the Myers effect.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 19:23:20 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gimon",
"Eric G.",
""
],
[
"Levi",
"Thomas S.",
""
]
] |
0706.3395 | Martin Laming | Cara E. Rakowski, J. Martin Laming and Susan T. Lepri | Ion Charge States in Halo CMEs: What can we Learn about the Explosion? | 20 pages, accepted by ApJ | Astrophys.J.667:602-609,2007 | 10.1086/520914 | null | astro-ph | null | We describe a new modeling approach to develop a more quantitative
understanding of the charge state distributions of the ions of various elements
detected in situ during halo Coronal Mass Ejection (CME) events by the Advanced
Composition Explorer (ACE) satellite. Using a model CME hydrodynamic evolution
based on observations of CMEs propagating in the plane of the sky and on
theoretical models, we integrate time dependent equations for the ionization
balance of various elements to compare with ACE data. We find that plasma in
the CME ``core'' typically requires further heating following filament
eruption, with thermal energy input similar to the kinetic energy input. This
extra heating is presumably the result of post eruptive reconnection. Plasma
corresponding to the CME ``cavity'' is usually not further ionized, since
whether heated or not, the low density gives freeze-in close the the Sun. The
current analysis is limited by ambiguities in the underlying model CME
evolution. Such methods are likely to reach their full potential when applied
to data to be acquired by STEREO when at optimum separation. CME evolution
observed with one spacecraft may be used to interpret CME charge states
detected by the other.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 19:36:21 GMT"
}
] | 2019-08-19T00:00:00 | [
[
"Rakowski",
"Cara E.",
""
],
[
"Laming",
"J. Martin",
""
],
[
"Lepri",
"Susan T.",
""
]
] |
0706.3396 | Oleg Lunin | Oleg Lunin | Strings ending on branes from supergravity | 81 pages, added refs | JHEP0709:093,2007 | 10.1088/1126-6708/2007/09/093 | EFI-07-17 | hep-th | null | We study geometries produced by brane intersections preserving eight
supercharges. Typical examples of such configurations are given by fundamental
strings ending on Dp branes and we construct gravity solutions describing such
intersections. The geometry is specified in terms of two functions obeying
coupled differential equations and the boundary conditions are determined by
distributions of D branes. We show that a consistency of type IIB supergravity
constrains the allowed positions of the branes. The shapes of branes derived
from gravity are found to be in a perfect agreement with profiles predicted by
the DBI analysis. We also discuss related 1/4-BPS systems in M theory.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 19:47:32 GMT"
},
{
"version": "v2",
"created": "Sun, 29 Jul 2007 00:25:33 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lunin",
"Oleg",
""
]
] |
0706.3397 | Andreas Boukas | Luigi Accardi and Andreas Boukas | Fock representation of the renormalized higher powers of white noise and
the Virasoro--Zamolodchikov--$w_{\infty} *$--Lie algebra | null | null | 10.1088/1751-8113/41/30/304001 | null | math-ph math.MP | null | The identification of the $*$--Lie algebra of the renormalized higher powers
of white noise (RHPWN) and the analytic continuation of the second quantized
Virasoro--Zamolodchikov--$w_{\infty} *$--Lie algebra of conformal field theory
and high-energy physics, was recently established in \cite{id} based on results
obtained in [1] and [2]. In the present paper we show how the RHPWN Fock
kernels must be truncated in order to be positive definite and we obtain a Fock
representation of the two algebras. We show that the truncated renormalized
higher powers of white noise (TRHPWN) Fock spaces of order $\geq 2$ host the
continuous binomial and beta processes.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 19:46:23 GMT"
},
{
"version": "v2",
"created": "Tue, 26 Jun 2007 06:30:47 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Accardi",
"Luigi",
""
],
[
"Boukas",
"Andreas",
""
]
] |
0706.3398 | Stanislav Jabuka | Joshua Greene, Stanislav Jabuka | The slice-ribbon conjecture for 3-stranded pretzel knots | 21 pages, 5 figures. Significantly expanded version, mistake in
previous proof corrected | null | null | null | math.GT | null | We determine the smooth concordance order of the 3-stranded pretzel knots
P(p,q,r) with p,q,r odd. We show that each one of finite order is, in fact,
ribbon, thereby proving the slice-ribbon conjecture for this family of knots.
As corollaries we give new proofs of results first obtained by Fintushel-Stern
and Casson-Gordon.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 18:08:14 GMT"
},
{
"version": "v2",
"created": "Tue, 7 Aug 2007 16:09:57 GMT"
}
] | 2007-08-07T00:00:00 | [
[
"Greene",
"Joshua",
""
],
[
"Jabuka",
"Stanislav",
""
]
] |
0706.3399 | Iain W. Stewart | Ambar Jain, Ira Z. Rothstein, Iain W. Stewart | Penguin Loops for Nonleptonic B-Decays in the Standard Model: Is there a
Penguin Puzzle? | 39 pages | null | null | MIT-CTP 3828 | hep-ph | null | We compute standard model penguin amplitudes in nonleptonic B-decays to light
charmless mesons using tree amplitude data to fix hadronic parameters. The
leading calculation is carried out for the alphas(mb) penguin contributions
from charm quark, up quark, and magnetic penguin loops in the NDR and HV
renormalization schemes. Power suppressed penguins that are proportional to the
chiral condensate are also computed using a new factorization formula for these
terms, which is derived working to all orders in alphas(sqrt{mb\Lambda}). We
demonstrate using SCET1 that this formula exhibits only small perturbative
phases and does not have endpoint singularities. Due to our use of data to fix
hadronic parameters we obtain significantly more accurate predictions for the
short-distance standard model penguin amplitudes than have been found in the
past. Analyzing data in B-> pi pi, B->K pi, and B->rho rho for the penguin
amplitudes we find that standard model short-distance imaginary parts are an
order of magnitude smaller than current measurements, while real parts are up
to a factor of two smaller with the correct sign. This difference is most
likely a consequence of long-distance charm contributions or new physics.
Constraints on the type of new physics that could help explain the data are
derived, and used to show that current data favors sizeable long-distance
strong phases.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 19:53:44 GMT"
},
{
"version": "v2",
"created": "Mon, 16 Jul 2007 21:18:51 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Jain",
"Ambar",
""
],
[
"Rothstein",
"Ira Z.",
""
],
[
"Stewart",
"Iain W.",
""
]
] |
0706.3400 | Andrew Fletcher | Andrew S. Fletcher | Channel-Adapted Quantum Error Correction | Ph.D. dissertation, 163 pages, 38 figures | null | null | null | quant-ph | null | Quantum error correction (QEC) is an essential concept for any quantum
information processing device. Typically, QEC is designed with minimal
assumptions about the noise process; this generic assumption exacts a high cost
in efficiency and performance. In physical systems, errors are not likely to be
arbitrary; rather we will have reasonable models for the structure of quantum
decoherence. We may choose quantum error correcting codes and recovery
operations that specifically target the most likely errors.
We present a convex optimization method to determine the optimal (in terms of
average entanglement fidelity) recovery operation for a given channel,
encoding, and information source. This is solvable via a semidefinite program
(SDP). We present computational algorithms to generate near-optimal recovery
operations structured to begin with a projective syndrome measurement. These
structured operations are more computationally scalable than the SDP required
for computing the optimal; we can thus numerically analyze longer codes. Using
Lagrange duality, we bound the performance of the structured recovery
operations and show that they are nearly optimal in many relevant cases.
We present two classes of channel-adapted quantum error correcting codes
specifically designed for the amplitude damping channel. These have
significantly higher rates with shorter block lengths than corresponding
generic quantum error correcting codes. Both classes are stabilizer codes, and
have good fidelity performance with stabilizer recovery operations. The
encoding, syndrome measurement, and syndrome recovery operations can all be
implemented with Clifford group operations.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 19:54:10 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Fletcher",
"Andrew S.",
""
]
] |
0706.3401 | Jens Eisert | D. Gross, J. Eisert, N. Schuch, D. Perez-Garcia | Measurement-based quantum computation beyond the one-way model | 21 pages, 7 figures | Phys. Rev. A 76, 052315 (2007) | 10.1103/PhysRevA.76.052315 | null | quant-ph | null | We introduce novel schemes for quantum computing based on local measurements
on entangled resource states. This work elaborates on the framework established
in [Phys. Rev. Lett. 98, 220503 (2007), quant-ph/0609149]. Our method makes use
of tools from many-body physics - matrix product states, finitely correlated
states or projected entangled pairs states - to show how measurements on
entangled states can be viewed as processing quantum information. This work
hence constitutes an instance where a quantum information problem - how to
realize quantum computation - was approached using tools from many-body theory
and not vice versa. We give a more detailed description of the setting, and
present a large number of new examples. We find novel computational schemes,
which differ from the original one-way computer for example in the way the
randomness of measurement outcomes is handled. Also, schemes are presented
where the logical qubits are no longer strictly localized on the resource
state. Notably, we find a great flexibility in the properties of the universal
resource states: They may for example exhibit non-vanishing long-range
correlation functions or be locally arbitrarily close to a pure state. We
discuss variants of Kitaev's toric code states as universal resources, and
contrast this with situations where they can be efficiently classically
simulated. This framework opens up a way of thinking of tailoring resource
states to specific physical systems, such as cold atoms in optical lattices or
linear optical systems.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 15:35:04 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gross",
"D.",
""
],
[
"Eisert",
"J.",
""
],
[
"Schuch",
"N.",
""
],
[
"Perez-Garcia",
"D.",
""
]
] |
0706.3402 | Ricardo Avila | Ricardo E. Avila | Diffusion kinetic parameters from bulk diffusion limited gas release
processes | Reduced version published as: R. E. Avila Jap. J. Appl. Phys. 43,
pp.7205-7206 (2004). (4 pages, 2 Figs.) | null | 10.1143/JJAP.43.7205 | null | cond-mat.mtrl-sci cond-mat.other | null | The diffusion of a bulk absorbed gas species out of spherical pebbles is
studied analytically, stressing the usefulness of the time integral of the
diffusion coefficient for analysis of arbitrary temperature schedule
experiments. Highly accurate approximations are introduced where the numeric
evaluation of the analytic expressions takes considerable time. A method is
proposed to extract the diffusion kinetic parameters from a single linear
heating ramp, namely, the activation energy of the diffusion coefficient and
the ratio of the corresponding preexponential factor to the radius of spherical
pebbles.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 21:47:49 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Avila",
"Ricardo E.",
""
]
] |
0706.3403 | Luciano da Fontoura Costa | Paulino R. Villas Boas, Francisco A. Rodrigues, Gonzalo Travieso and
Luciano da F. Costa | Border trees of complex networks | 5 pages, 1 figure, 2 tables. A working manuscript, comments and
suggestions welcomed | null | 10.1088/1751-8113/41/22/224005 | null | physics.comp-ph | null | The comprehensive characterization of the structure of complex networks is
essential to understand the dynamical processes which guide their evolution.
The discovery of the scale-free distribution and the small world property of
real networks were fundamental to stimulate more realistic models and to
understand some dynamical processes such as network growth. However, properties
related to the network borders (nodes with degree equal to one), one of its
most fragile parts, remain little investigated and understood. The border nodes
may be involved in the evolution of structures such as geographical networks.
Here we analyze complex networks by looking for border trees, which are defined
as the subgraphs without cycles connected to the remainder of the network
(containing cycles) and terminating into border nodes. In addition to
describing an algorithm for identification of such tree subgraphs, we also
consider a series of their measurements, including their number of vertices,
number of leaves, and depth. We investigate the properties of border trees for
several theoretical models as well as real-world networks.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 20:20:25 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Boas",
"Paulino R. Villas",
""
],
[
"Rodrigues",
"Francisco A.",
""
],
[
"Travieso",
"Gonzalo",
""
],
[
"Costa",
"Luciano da F.",
""
]
] |
0706.3404 | Shangli Ou | Shangli Ou, Jianghui Ji, Lin Liu, Xiaomeng Peng | Disk-Planet Interaction Simulations: (I) Baroclinic Generation of
Vortensity and Non-Axisymmetric Rossby-Wave-Instability | ~ 30 pages, Ap. J. in press | null | 10.1086/521012 | null | astro-ph | null | We use a multi-dimensional hydrodynamics code to study the gravitational
interaction between an embedded planet and a protoplanetary disk with emphasis
on the generation of vortensity (potential vorticity) through a Baroclinic
Instability and subsequent development of Rossby-Wave-Instability (RWI). It is
found that the generation of potential vorticity is very common and effective
in non-barotropic disks through the Baroclinic Instability, especially within
the coorbital region. Our results also complement previous studies by
\citet{KLL03} that non-axisymmetric RWIs are likely to develop at local minima
of potential vorticity distribution that are generated by the interaction
between a planet and a inviscid barotropic disk. This second instability
appears to be very common and robust, regardless of the equation of state,
initial density distribution, and rotational law of the disk. The development
of RWIs results in non-axisymmetric density blobs, which exert stronger torques
onto the planet when they travel in the vicinity of the planet. As a result of
that, large amplitude oscillations are introduced to the time behavior of the
total torque acted on the planet by the disk. In our current simulations, RWIs
do not change the overall picture of inward orbital migration but bring in a
non-monotonic behavior to the migration speed. As a side effect, RWIs also
introduce interesting structures into the disk. These structures may help the
formation of Earth-like planets in the Habitable Zone or Hot Earths interior to
a close-in giant planet.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 20:20:49 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ou",
"Shangli",
""
],
[
"Ji",
"Jianghui",
""
],
[
"Liu",
"Lin",
""
],
[
"Peng",
"Xiaomeng",
""
]
] |
0706.3405 | Arseny Akopyan | Arseny Akopyan | On Point Coverings of Boxes in $\mathbb R^d$ | 5 pages, 1 figures | Intersection of Parallelepipeds in $\mathbb R^d$ // Mathematical
Notes, V 83, N. 1 (2008), pp 153-156 | null | null | math.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Families of boxes in $\mathbb R^d$ are considered. In the paper an upper
bound on the size of a minimum transversal in terms of the space dimension and
the independence number of the given family was improved.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 19:09:52 GMT"
},
{
"version": "v2",
"created": "Tue, 26 Jun 2007 07:02:58 GMT"
},
{
"version": "v3",
"created": "Wed, 24 Oct 2007 19:22:46 GMT"
},
{
"version": "v4",
"created": "Tue, 21 Oct 2008 10:14:19 GMT"
}
] | 2008-10-21T00:00:00 | [
[
"Akopyan",
"Arseny",
""
]
] |
0706.3406 | Ganpathy Murthy | Ganpathy Murthy | A Universal Interacting Crossover Regime in Two-Dimensional Quantum Dots | 4 pages, 1 figure | null | 10.1103/PhysRevB.77.073309 | null | cond-mat.mes-hall | null | Interacting electrons in quantum dots with large Thouless number $g$ in the
three classical random matrix symmetry classes are well-understood. When a
specific type of spin-orbit coupling known to be dominant in two dimensional
semiconductor quantum dots is introduced, we show that a new interacting
quantum critical crossover energy scale emerges and low-energy quasiparticles
generically have a decay width proportional to their energy. The low-energy
physics of this system is an example of a universal interacting crossover
regime.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 20:34:03 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Murthy",
"Ganpathy",
""
]
] |
0706.3407 | Jeronimo Bernard-Salas | S.R. Pottasch, J. Bernard-Salas, T.L. Roellig | Abundances of Planetary Nebula M1-42 | 9 pages, 8 tables, 1 figure. Accepted for publication in A&A | null | 10.1051/0004-6361:20077381 | null | astro-ph | null | The spectra of the planetary nebula M1-42 is reanalysed using spectral
measurements made in the mid-infrared with the Spitzer Space Telescope. The aim
is to determine the chemical composition of this object. We also make use of
ISO, IUE and ground based spectra. Abundances determined from the mid- and
far-infrared lines, which are insensitive to electron temperature, are used as
the basis for the determination of the composition, which are found to
substantially differ from earlier results. High values of neon, argon and
sulfur are found. They are higher than in other PN, with the exception of
NGC6153, a nebula of very similar abundances. The high values of helium and
nitrogen found indicate that the second dredge-up and hot bottom burning has
occurred in the course of evolution and that the central star was originally
more massive than 4Msun. The present temperature and luminosity of the central
star is determined and at first sight may be inconsistent with such a high
mass.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 20:40:00 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Pottasch",
"S. R.",
""
],
[
"Bernard-Salas",
"J.",
""
],
[
"Roellig",
"T. L.",
""
]
] |
0706.3408 | Brian C. Tiburzi | Jie Hu, Fu-Jiun Jiang, Brian C. Tiburzi | Current Renormalization in Finite Volume | 15pp., 4 figs, wording and discussion improved | Phys.Lett.B653:350-357,2007 | 10.1016/j.physletb.2007.07.060 | null | hep-lat hep-ph nucl-th | null | For finite volume field theories with discrete translational invariance,
conserved currents can be additively renormalized by infrared effects. We
demonstrate this for pions using chiral perturbation theory coupled to
electromagnetism in a periodic box. Gauge invariant single particle effective
theories are constructed to explain these results. In such theories, current
renormalization arises from operators involving the zero mode of the gauge
field. No contradictions with Ward identities, or low-energy theorems are
encountered.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 20:51:07 GMT"
},
{
"version": "v2",
"created": "Tue, 10 Jul 2007 17:50:18 GMT"
},
{
"version": "v3",
"created": "Tue, 24 Jul 2007 17:49:36 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hu",
"Jie",
""
],
[
"Jiang",
"Fu-Jiun",
""
],
[
"Tiburzi",
"Brian C.",
""
]
] |
0706.3409 | Kyoungchul Kong | Bogdan A. Dobrescu, Dan Hooper, Kyoungchul Kong, Rakhi Mahbubani | Spinless photon dark matter from two universal extra dimensions | 22 pages. Figure 7 corrected, leading to improved prospects for
direct detection. Some clarifying remarks included | JCAP 0710:012,2007 | 10.1088/1475-7516/2007/10/012 | FERMILAB-PUB-07-274-A-T | hep-ph astro-ph | null | We explore the properties of dark matter in theories with two universal extra
dimensions, where the lightest Kaluza-Klein state is a spin-0 neutral particle,
representing a six-dimensional photon polarized along the extra dimensions.
Annihilation of this 'spinless photon' proceeds predominantly through Higgs
boson exchange, and is largely independent of other Kaluza-Klein particles. The
measured relic abundance sets an upper limit on the spinless photon mass of 500
GeV, which decreases to almost 200 GeV if the Higgs boson is light. The
phenomenology of this dark matter candidate is strikingly different from
Kaluza-Klein dark matter in theories with one universal extra dimension.
Elastic scattering of the spinless photon with quarks is helicity suppressed,
making its direct detection challenging, although possible at upcoming
experiments. The prospects for indirect detection with gamma rays and
antimatter are similar to those of neutralinos. The rates predicted at neutrino
telescopes are below the sensitivity of next-generation experiments.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 19:52:46 GMT"
},
{
"version": "v2",
"created": "Thu, 4 Oct 2007 15:17:21 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Dobrescu",
"Bogdan A.",
""
],
[
"Hooper",
"Dan",
""
],
[
"Kong",
"Kyoungchul",
""
],
[
"Mahbubani",
"Rakhi",
""
]
] |
0706.3410 | Gregory Moore | Alexei Kitaev, Gregory W. Moore, Kevin Walker | Noncommuting Flux Sectors in a Tabletop Experiment | 17 pp. harvmac b-mode; 10 figures | null | null | null | hep-th | null | We show how one can use superconductors and Josephson junctions to create a
laboratory system which can explore the groundstates of the free
electromagnetic field in a 3-manifold with torsion in its cohomology.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 21:14:20 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Kitaev",
"Alexei",
""
],
[
"Moore",
"Gregory W.",
""
],
[
"Walker",
"Kevin",
""
]
] |
0706.3411 | Stephan Ritter | Ferdinand Brennecke, Tobias Donner, Stephan Ritter, Thomas Bourdel,
Michael K\"ohl and Tilman Esslinger | Cavity QED with a Bose-Einstein condensate | 6 pages, 4 figures; version accepted for publication in Nature;
updated Fig. 4; changed atom numbers due to new calibration | Nature 450, 268-271 (2007) | 10.1038/nature06120 | null | quant-ph cond-mat.other | null | Cavity quantum electrodynamics (cavity QED) describes the coherent
interaction between matter and an electromagnetic field confined within a
resonator structure, and is providing a useful platform for developing concepts
in quantum information processing. By using high-quality resonators, a strong
coupling regime can be reached experimentally in which atoms coherently
exchange a photon with a single light-field mode many times before dissipation
sets in. This has led to fundamental studies with both microwave and optical
resonators. To meet the challenges posed by quantum state engineering and
quantum information processing, recent experiments have focused on laser
cooling and trapping of atoms inside an optical cavity. However, the tremendous
degree of control over atomic gases achieved with Bose-Einstein condensation
has so far not been used for cavity QED. Here we achieve the strong coupling of
a Bose-Einstein condensate to the quantized field of an ultrahigh-finesse
optical cavity and present a measurement of its eigenenergy spectrum. This is a
conceptually new regime of cavity QED, in which all atoms occupy a single mode
of a matter-wave field and couple identically to the light field, sharing a
single excitation. This opens possibilities ranging from quantum communication
to a wealth of new phenomena that can be expected in the many-body physics of
quantum gases with cavity-mediated interactions.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 21:13:30 GMT"
},
{
"version": "v2",
"created": "Tue, 6 Nov 2007 14:00:38 GMT"
}
] | 2007-11-08T00:00:00 | [
[
"Brennecke",
"Ferdinand",
""
],
[
"Donner",
"Tobias",
""
],
[
"Ritter",
"Stephan",
""
],
[
"Bourdel",
"Thomas",
""
],
[
"Köhl",
"Michael",
""
],
[
"Esslinger",
"Tilman",
""
]
] |
0706.3412 | Blai Bonet | Nerio Borges, Blai Bonet | On Canonical Forms of Complete Problems via First-order Projections | 9 pages | null | null | null | cs.CC | null | The class of problems complete for NP via first-order reductions is known to
be characterized by existential second-order sentences of a fixed form. All
such sentences are built around the so-called generalized IS-form of the
sentence that defines Independent-Set. This result can also be understood as
that every sentence that defines a NP-complete problem P can be decomposed in
two disjuncts such that the first one characterizes a fragment of P as hard as
Independent-Set and the second the rest of P. That is, a decomposition that
divides every such sentence into a quotient and residue modulo Independent-Set.
In this paper, we show that this result can be generalized over a wide
collection of complexity classes, including the so-called nice classes.
Moreover, we show that such decomposition can be done for any complete problem
with respect to the given class, and that two such decompositions are
non-equivalent in general. Interestingly, our results are based on simple and
well-known properties of first-order reductions.ow that this result can be
generalized over a wide collection of complexity classes, including the
so-called nice classes. Moreover, we show that such decomposition can be done
for any complete problem with respect to the given class, and that two such
decompositions are non-equivalent in general. Interestingly, our results are
based on simple and well-known properties of first-order reductions.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 21:27:06 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Borges",
"Nerio",
""
],
[
"Bonet",
"Blai",
""
]
] |
0706.3413 | Hua Wu | Hua Wu and D. I. Khomskii | Orbital ordering in the ferromagnetic insulator Cs$_2$AgF$_4$ from first
principles | 5 pages, 4 figures, 1 table; a few energy/moment entries in Table I
are corrected due to a proper treatment of the Ag 4s semicore state | Phys. Rev. B 76, 155115 (2007) | 10.1103/PhysRevB.76.155115 | null | cond-mat.mtrl-sci cond-mat.str-el | null | We found, using density-functional theory calculations within the generalized
gradient approximation, that Cs$_2$AgF$_4$ is stabilized in the insulating
orthorhombic phase rather than in the metallic tetragonal phase. The lattice
distortion present in the orthorhombic phase corresponds to the
$x^2-z^2$/$y^2-z^2$ hole-orbital ordering of the Ag$^{2+}$ $4d^9$ ions, and
this orbital ordering leads to the observed ferromagnetism, as confirmed by the
present total-energy calculations. This picture holds in the presence of
moderate 4d-electron correlation. The results are compared with the picture of
ferromagnetism based on the metallic tetragonal phase.
| [
{
"version": "v1",
"created": "Fri, 22 Jun 2007 21:30:39 GMT"
},
{
"version": "v2",
"created": "Tue, 28 Aug 2007 07:34:34 GMT"
}
] | 2007-10-23T00:00:00 | [
[
"Wu",
"Hua",
""
],
[
"Khomskii",
"D. I.",
""
]
] |
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