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sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0706.2614 | Yaroslav Pavlyuchenkov Dr. | Ya. Pavlyuchenkov and C. P. Dullemond | Dust crystallinity in protoplanetary disks: the effect of
diffusion/viscosity ratio | 9 pages, 5 figures, accepted for publication in A&A | null | 10.1051/0004-6361:20077317 | null | astro-ph | null | The process of turbulent radial mixing in protoplanetary disks has strong
relevance to the analysis of the spatial distribution of crystalline dust
species in disks around young stars and to studies of the composition of
meteorites and comets in our own solar system.
A debate has gone on in the recent literature on the ratio of the effective
viscosity coefficient $\nu$ (responsible for accretion) to the turbulent
diffusion coefficient $D$ (responsible for mixing). Numerical
magneto-hydrodynamic simulations have yielded values between $\nu/D\simeq 10$
(Carballido, Stone & Pringle, 2005) and $\nu/D\simeq 0.85$ (Johansen & Klahr,
2005}). Here we present two analytic arguments for the ratio $\nu/D=1/3$ which
are based on elegant, though strongly simplified assumptions. We argue that
whichever of these numbers comes closest to reality may be determined {\em
observationally} by using spatially resolved mid-infrared measurements of
protoplanetary disks around Herbig stars. If meridional flows are present in
the disk, then we expect less abundance of crystalline dust in the surface
layers, a prediction which can likewise be observationally tested with
mid-infrared interferometers.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 14:46:59 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Pavlyuchenkov",
"Ya.",
""
],
[
"Dullemond",
"C. P.",
""
]
] |
0706.2615 | Salvatore Capozziello | S. Capozziello, P.K.S. Dunsby, E. Piedipalumbo, C. Rubano | Constraining scalar-tensor quintessence by cosmic clocks | 13 pages, 8 figures. to be published in Astron & Astroph | null | 10.1051/0004-6361:20077827 | null | astro-ph gr-qc | null | Scalar-tensor quintessence models can be constrained by identifying suitable
cosmic clocks which allow to select confidence regions for cosmological
parameters. In particular, we constrain the characterizing parameters of
non-minimally coupled scalar-tensor cosmological models which admit exact
solutions of the Einstein field equations. Lookback time to galaxy clusters at
low intermediate, and high redshifts is considered. The high redshift
time-scale problem is also discussed in order to select other cosmic clocks
such as quasars.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 14:48:01 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Capozziello",
"S.",
""
],
[
"Dunsby",
"P. K. S.",
""
],
[
"Piedipalumbo",
"E.",
""
],
[
"Rubano",
"C.",
""
]
] |
0706.2616 | Roald Sosnovskiy | Roald Sosnovskiy | The gravitational energy for stationary space-time | 4 pages | null | null | null | gr-qc | null | It is prove, that the gravity field energy formulas obtained for static
systems on the ground of local energy conservation law by test-particles fall,
is suitable for stationary systems.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 14:59:58 GMT"
}
] | 2007-06-19T00:00:00 | [
[
"Sosnovskiy",
"Roald",
""
]
] |
0706.2617 | Marek Ku\'s | Janusz Grabowski, Marek Kus and Giuseppe Marmo | On the relation between states and maps in infinite dimensions | 19 pages | null | null | null | math-ph math.MP | null | Relations between states and maps, which are known for quantum systems in
finite-dimensional Hilbert spaces, are formulated rigorously in geometrical
terms with no use of coordinate (matrix) interpretation. In a tensor product
realization they are represented simply by a permutation of factors. This leads
to natural generalizations for infinite-dimensional Hilbert spaces and a simple
proof of a generalized Choi Theorem. The natural framework is based on spaces
of Hilbert-Schmidt operators $\mathcal{L}_2(\mathcal{H}_2,\mathcal{H}_1)$ and
the corresponding tensor products $\mathcal{H}_1\otimes\mathcal{H}_2^*$ of
Hilbert spaces. It is proved that the corresponding isomorphisms cannot be
naturally extended to compact (or bounded) operators, nor reduced to the
trace-class operators. On the other hand, it is proven that there is a natural
continuous map
$\mathcal{C}:\mathcal{L}_1(\mathcal{L}_2(\mathcal{H}_2,\mathcal{H}_1))\to
\mathcal{L}_\infty(\mathcal{L}(\mathcal{H}_2),\mathcal{L}_1(\mathcal{H}_1))$
from trace-class operators on $\mathcal{L}_2(\mathcal{H}_2,\mathcal{H}_1)$
(with the nuclear norm) into compact operators mapping the space of all bounded
operators on $\mathcal{H}_2$ into trace class operators on $\mathcal{H}_1$
(with the operator-norm). Also in the infinite-dimensional context, the Schmidt
measure of entanglement and multipartite generalizations of state-maps
relations are considered in the paper.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 15:00:43 GMT"
}
] | 2007-06-19T00:00:00 | [
[
"Grabowski",
"Janusz",
""
],
[
"Kus",
"Marek",
""
],
[
"Marmo",
"Giuseppe",
""
]
] |
0706.2618 | Michael Sadovskii | E.Z. Kuchinskii, I.A. Nekrasov, M.V. Sadovskii | Mott-Hubbard Transition and Anderson Localization: Generalized Dynamical
Mean-Field Theory Approach | 15 pages, 16 figures | JETP 106 (2008) 581 | 10.1134/S1063776108030187 | null | cond-mat.str-el cond-mat.dis-nn | null | Density of states, dynamic (optical) conductivity and phase diagram of
strongly correlated and strongly disordered paramagnetic Anderson-Hubbard model
are analyzed within the generalized dynamical mean field theory (DMFT+\Sigma
approximation). Strong correlations are accounted by DMFT, while disorder is
taken into account via the appropriate generalization of self-consistent theory
of localization. The DMFT effective single impurity problem is solved by
numerical renormalization group (NRG) and we consider the three-dimensional
system with semi-elliptic density of states. Correlated metal, Mott insulator
and correlated Anderson insulator phases are identified via the evolution of
density of states and dynamic conductivity, demonstrating both Mott-Hubbard and
Anderson metal-insulator transition and allowing the construction of complete
zero-temperature phase diagram of Anderson-Hubbard model. Rather unusual is the
possibility of disorder induced Mott insulator to metal transition.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 15:01:30 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kuchinskii",
"E. Z.",
""
],
[
"Nekrasov",
"I. A.",
""
],
[
"Sadovskii",
"M. V.",
""
]
] |
0706.2619 | Laurent Doyen | Krishnendu Chatterjee, Laurent Doyen, Thomas A. Henzinger,<br>
Jean-Francois Raskin | Algorithms for Omega-Regular Games with Imperfect Information | 24 pages. A preliminary version of this paper appeared in the
Proceedings of the International Conference for Computer Science Logic (CSL),
Lecture Notes in Computer Science 4207, Springer, 2006, pp. 287-302 | Logical Methods in Computer Science, Volume 3, Issue 3 (July 27,
2007) lmcs:1094 | 10.2168/LMCS-3(3:4)2007 | null | cs.LO cs.GT | null | We study observation-based strategies for two-player turn-based games on
graphs with omega-regular objectives. An observation-based strategy relies on
imperfect information about the history of a play, namely, on the past sequence
of observations. Such games occur in the synthesis of a controller that does
not see the private state of the plant. Our main results are twofold. First, we
give a fixed-point algorithm for computing the set of states from which a
player can win with a deterministic observation-based strategy for any
omega-regular objective. The fixed point is computed in the lattice of
antichains of state sets. This algorithm has the advantages of being directed
by the objective and of avoiding an explicit subset construction on the game
graph. Second, we give an algorithm for computing the set of states from which
a player can win with probability 1 with a randomized observation-based
strategy for a Buechi objective. This set is of interest because in the absence
of perfect information, randomized strategies are more powerful than
deterministic ones. We show that our algorithms are optimal by proving matching
lower bounds.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 15:02:02 GMT"
},
{
"version": "v2",
"created": "Fri, 27 Jul 2007 14:56:14 GMT"
},
{
"version": "v3",
"created": "Fri, 2 Nov 2007 17:01:47 GMT"
}
] | 2015-07-01T00:00:00 | [
[
"Chatterjee",
"Krishnendu",
""
],
[
"Doyen",
"Laurent",
""
],
[
"Henzinger",
"Thomas A.",
""
],
[
"Raskin",
"<br> Jean-Francois",
""
]
] |
0706.2620 | Yao Cheng | Yao Cheng, Bing Xia, Zhongming Wang | Rhodium Mossbauer Supperadiance Induced by Liquid-Nitrogen Cooling | 10 pages | null | null | null | quant-ph physics.atom-ph | null | In the previous report, we have demonstrated cascade branching channels of
the multipolar E3 transition of rhodium Mossbauer gamma via the time- and
energy-resolved spectroscopy. Moreover, superradiance in the Borrmann channel
from inverted nuclei gives gamma entanglement. In this letter, we report
further four observations of superradiance and its associated gamma
entanglement at the liquid-nitrogen temperature, i.e. (i) speed-up decay, (ii)
immediate recovery of the speed-up decay after quenching, (iii) simultaneous
suppression of gamma and K lines, and (iv) enhanced multiple ionizations.
Anisotropic superradiant channels open by quenching and recover back
immediately after quenching. Enhanced K satellites and K hypersatellites
induced by cooling are attributed to the inelastic scattering of more than
three entangled gammas.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 19:11:12 GMT"
}
] | 2007-06-19T00:00:00 | [
[
"Cheng",
"Yao",
""
],
[
"Xia",
"Bing",
""
],
[
"Wang",
"Zhongming",
""
]
] |
0706.2621 | George Bogoslovsky | George Bogoslovsky | Some physical displays of the space anisotropy relevant to the
feasibility of its being detected at a laboratory | 11 pages, to appear in Proc. Int. Conf. "Physical Interpretations of
Relativity Theory" | null | null | null | gr-qc | null | The impact of local space anisotropy on the transverse Doppler effect is
examined. Two types of laboratory experiments aimed at seeking and measuring
the local space anisotropy are proposed. In terms of the conventional special
relativity theory, which treats 3D space to be locally isotropic, the
experiments are of the type of ``null-experiments''. In the first-type
experiments, a feasible Doppler shift of frequency is measured by the
M\"ossbauer effect, with the M\"ossbauer source and absorber being located at
two identical and diametrically opposed distances from the center of a rapidly
rotating rotor, while the $\gamma$-quanta are recorded by two stationary and
oppositely positioned proportional counters. Either of the counters records
only those $\gamma$-quanta that passed through the absorber at the moment of
the passage of the latter near a counter. The second-type experiments are made
using the latest radio physics techniques for generating monochromatic
oscillations and for recording weak signals. The effect expected due to space
anisotropy consists in frequency modulation of the harmonic oscillations coming
to a receiver that rotates at a constant velocity around the monochromatic wave
emitter. In this case the modulation depth proves to be proportional to the
space anisotropy magnitude.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 15:21:13 GMT"
}
] | 2007-06-19T00:00:00 | [
[
"Bogoslovsky",
"George",
""
]
] |
0706.2622 | Michelle Lanyon-Foster | M. M. Lanyon-Foster, C. J. Conselice, M. R. Merrifield | Structure Through Colour: A Pixel Approach Towards Understanding
Galaxies | 16 pages, 20 figures, MNRAS, accepted. For high resolution figures
see: http://www.nottingham.ac.uk/~ppxmml/lcm_2007.pdf | null | 10.1111/j.1365-2966.2007.12132.x | null | astro-ph | null | We present a study of pixel Colour Magnitude Diagrams (pCMDs) for a sample of
69 nearby galaxies chosen to span a wide range of Hubble types. Our goal is to
determine how useful a pixel approach is for studying galaxies according to
their stellar light distributions and content. The galaxy images were analysed
on a pixel-by-pixel basis to reveal the structure of the individual pCMDs. We
find that the average surface brightness (or projected mass density) in each
pixel varies according to galaxy type. Early-type galaxies exihibit a clear
``prime sequence'' and some pCMDs of face-on spirals reveal ``inverse-L''
structures. We find that the colour dispersion at a given magnitude is found to
be approximately constant in early-type galaxies but this quantity varies in
the mid and late-types. We investigate individual galaxies and find that the
pCMDs can be used to pick out morphological features. We discuss the discovery
of ``Red Hooks'' in the pCMDs of six early-type galaxies and two spirals and
postulate their origins. We develop quantitative methods to characterise the
pCMDs, including measures of the blue-to-red light ratio and colour
distributions of each galaxy and we organise these by morphological type. We
compare the colours of the pixels in each galaxy with the stellar population
models of Bruzual & Charlot (2003) to calculate star formation histories for
each galaxy type and compare these to the stellar mass within each pixel. Maps
of pixel stellar mass and mass-to-light ratio are compared to galaxy images. We
apply the pCMD technique to three galaxies in the Hubble Ultra Deep Field to
test the usefulness of the analysis at high redshift. We propose that these
results can be used as part of a new system of automated classification of
galaxies that can be applied at high redshift.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 15:28:08 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Lanyon-Foster",
"M. M.",
""
],
[
"Conselice",
"C. J.",
""
],
[
"Merrifield",
"M. R.",
""
]
] |
0706.2623 | Muxin Han | Muxin Han | Quantum Dyanmics of Loop Quantum Gravity | 95 pages, MSc Thesis (Advisor: Dr. Jorge Pullin), Louisiana State
University | null | null | null | gr-qc hep-th math-ph math.MP | null | In the last 20 years, loop quantum gravity, a background independent approach
to unify general relativity and quantum mechanics, has been widely
investigated. The aim of loop quantum gravity is to construct a mathematically
rigorous, background independent, nonperturbative quantum theory for the
Lorentzian gravitational field on a four-dimensional manifold. In this
approach, the principles of quantum mechanics are combined with those of
general relativity naturally. Such a combination provides us a picture of
"quantum Riemannian geometry", which is discrete at a fundamental scale. In the
investigation of quantum dynamics, the classical expressions of constraints are
quantized as operators. The quantum evolution is contained in the solutions of
the quantum constraint equations. On the other hand, the semi-classical
analysis has to be carried out in order to test the semiclassical limit of the
quantum dynamics.
In this thesis, the structure of the dynamical theory in loop quantum gravity
is presented pedagogically. The outline is as follows: first we review the
classical formalism of general relativity as a dynamical theory of connections.
Then the kinematical Ashtekar-Isham-Lewandowski representation is introduced as
a foundation of loop quantum gravity. We discuss the construction of a
Hamiltonian constraint operator and the master constraint programme, for both
the cases of pure gravity and matter field coupling. Finally, some strategies
are discussed concerning testing the semiclassical limit of the quantum
dynamics.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 15:31:33 GMT"
}
] | 2007-06-25T00:00:00 | [
[
"Han",
"Muxin",
""
]
] |
0706.2624 | Alexander Kashlinsky | A. Kashlinsky, R. G. Arendt, J. Mather, S. H. Moseley | Demonstrating the negligible contribution of optical ACS/HST galaxies to
source-subtracted cosmic infrared background fluctuations in deep
IRAC/Spitzer images | Ap.J.Letters, in press. Minor revisions to mathc the accepted version | Ap.J.(Letters), 2007, vol. 666, L1 | 10.1086/521551 | null | astro-ph | null | We study the possible contribution of optical galaxies detected with the {\it
Hubble} ACS instrument to the near-IR cosmic infrared (CIB) fluctuations in
deep {\it Spitzer} images. The {\it Spitzer} data used in this analysis are
obtained in the course of the GOODS project from which we select four
independent $10^\prime\times10^\prime$ regions observed at both 3.6 and 4.5
\um. ACS source catalogs for all of these areas are used to construct maps
containing only their emissions in the ACS $B, V, i, z$-bands. We find that
deep Spitzer data exhibit CIB fluctuations remaining after removal of
foreground galaxies of a very different clustering pattern at both 3.6 and 4.5
\um than the ACS galaxies could contribute. We also find that there are very
good correlations between the ACS galaxies and the {\it removed} galaxies in
the Spitzer maps, but practically no correlations remain with the residual
Spitzer maps used to identify the CIB fluctuations. These contributions become
negligible on larger scales used to probe the CIB fluctuations arising from
clustering. This means that the ACS galaxies cannot contribute to the
large-scale CIB fluctuations found in the residual Spitzer data. The absence of
their contributions also means that the CIB fluctuations arise at $z\gsim 7.5$
as the Lyman break of their sources must be redshifted past the longest ACS
band, or the fluctuations have to originate in the more local but extremely low
luminosity galaxies.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 15:42:23 GMT"
},
{
"version": "v2",
"created": "Thu, 12 Jul 2007 13:29:59 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kashlinsky",
"A.",
""
],
[
"Arendt",
"R. G.",
""
],
[
"Mather",
"J.",
""
],
[
"Moseley",
"S. H.",
""
]
] |
0706.2625 | Javier Mu\~noz-Garc\'ia | Javier Mu\~noz-Garc\'ia, Luis V\'azquez, Rodolfo Cuerno, Jos\'e A.
S\'anchez-Garc\'ia, Mario Castro and Ra\'ul Gago | Self-organized surface nanopatterning by ion beam sputtering | To appear in Lecture Notes on Nanoscale Science and Technology,
edited by Z. Wang (Springer, Heidelberg) | null | null | null | cond-mat.mtrl-sci | null | The production of nanopatterns on the surfaces of targets irradiated by ion
beams at low and intermediate energies has developed during the present decade
to a salient degree of control over the main pattern features. However, there
is still a wide experimental scatter in the type and relevance of various
dynamic interfacial properties induced by this technique as a function of
system type and parameters. In parallel, diverse theoretical models exist that
differ in their capabilities to reproduce such a wide range of experimental
features. We provide an overview of the most recent studies of nanoripple and
dot production by ion-beam sputtering, with special attention to the comparison
between experiments and (continuum) models, and with a focus on those issues
that remain open or, at least, ambiguous. These are perhaps more evident for
the case of nanodot patterns on amorphizable targets than for the case of
nanoripples due, possibly, to the relative novelty of the former. The pattern
properties to be considered are those of potential increased technological
importance, such as the variation of nanodot size with parameters like ion
energy, target temperature and sputtering time (i.e., fluence), as well as the
conditions under which the quality of the pattern order is enhanced, issues
such as wavelength coarsening and order enhancement becoming relevant.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 15:25:57 GMT"
}
] | 2016-08-14T00:00:00 | [
[
"Muñoz-García",
"Javier",
""
],
[
"Vázquez",
"Luis",
""
],
[
"Cuerno",
"Rodolfo",
""
],
[
"Sánchez-García",
"José A.",
""
],
[
"Castro",
"Mario",
""
],
[
"Gago",
"Raúl",
""
]
] |
0706.2626 | Luis L. Sanchez. Soto | A. B. Klimov, J. L. Romero, G. Bjork and L. L. Sanchez-Soto | Geometrical approach to mutually unbiased bases | 10 pages. Some typos in the journal version have been corrected | J. Phys. A 40, 3987 (2007) | 10.1088/1751-8113/40/14/014 | null | quant-ph | null | We propose a unifying phase-space approach to the construction of mutually
unbiased bases for a two-qubit system. It is based on an explicit
classification of the geometrical structures compatible with the notion of
unbiasedness. These consist of bundles of discrete curves intersecting only at
the origin and satisfying certain additional properties. We also consider the
feasible transformations between different kinds of curves and show that they
correspond to local rotations around the Bloch-sphere principal axes. We
suggest how to generalize the method to systems in dimensions that are powers
of a prime.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 15:48:35 GMT"
}
] | 2007-06-19T00:00:00 | [
[
"Klimov",
"A. B.",
""
],
[
"Romero",
"J. L.",
""
],
[
"Bjork",
"G.",
""
],
[
"Sanchez-Soto",
"L. L.",
""
]
] |
0706.2627 | N. W. Evans | M. Fellhauer (1), N.W. Evans (1), V. Belokurov (1), M.I. Wilkinson
(1,2), G. Gilmore (1) ((1) Cambridge, (2) Leicester) | The Tidal Tails of NGC 5466 | MNRAS, in press | null | 10.1111/j.1365-2966.2007.12111.x | null | astro-ph | null | The study of substructure in the stellar halo of the Milky Way has made a lot
of progress in recent years, especially with the advent of surveys like the
Sloan Digital Sky Survey. Here, we study the newly discovered tidal tails of
the Galactic globular cluster NGC 5466. By means of numerical simulations, we
reproduce the shape, direction and surface density of the tidal tails, as well
as the structural and kinematical properties of the present-day NGC 5466.
Although its tails are very extended in SDSS data (> 45 degrees), NGC 5466 is
only losing mass slowly at the present epoch and so can survive for probably a
further Hubble time. The effects of tides at perigalacticon and disc crossing
are the dominant causes of the slow dissolution of NGC 5466, accounting for
about 60 % of the mass loss over the course of its evolution. The morphology of
the tails provides a constraint on the proper motion -- the observationally
determined proper motion has to be refined (within the stated error margins) to
match the location of the tidal tails.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 15:54:50 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Fellhauer",
"M.",
"",
"Cambridge"
],
[
"Evans",
"N. W.",
"",
"Cambridge"
],
[
"Belokurov",
"V.",
"",
"Cambridge"
],
[
"Wilkinson",
"M. I.",
"",
"Cambridge",
"Leicester"
],
[
"Gilmore",
"G.",
"",
"Cambridge"
]
] |
0706.2628 | Yao Cheng | Yao Cheng and Bing Xia | Phase Transition of Trapped Nuclear Exciton of Long-lived Rhodium
Mossbauer States | Revised by additional discovery | null | null | null | quant-ph gr-qc physics.atom-ph | null | We report experimental observations of the long-lived rhodium Mossbauer
emissions by the time- and energy-resolved spectroscopy. The extraordinary
observations manifest the open-up of photonic band gap in analogy to the
superconducting gap of remarkable symmetry breakings at transition point. These
observations are of potential importance for detecting gravitational waves and
development of the two-photon gamma laser. Firstly, phase transitions shown by
spectral evolution of characteristic emissions reveal the different aggregate
exciton orderings at room temperature. Six different phases are identified by
spectra profiles emitted from the color centers. Secondly, the cascade
branching of the multipolar nuclear transition is discovered being the
spontaneous cascade down-conversion to generate entangled gammas. The
macroscopic angular distribution of entangled gammas from the polycrystalline
sample manifests a global photon-nucleus-photon bound state across the grain
boundaries. Thirdly, the gamma-energy distributions depending on exciton phases
reveal the photonic band gap typically on the order of several hundred eV.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 19:26:21 GMT"
},
{
"version": "v2",
"created": "Wed, 11 Jul 2007 14:53:19 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Cheng",
"Yao",
""
],
[
"Xia",
"Bing",
""
]
] |
0706.2629 | Chow-Choong Ngeow | S. Kanbur (SUNY-Oswego), C. Ngeow (UIUC) and G. Feiden (SUNY-Oswego) | Period-color and amplitude-color relations in classical Cepheid
variables V: The Small Magellanic Cloud Cepheid models | 10 pages, 6 figures and 6 tables, MNRAS accepted | null | 10.1111/j.1365-2966.2007.12123.x | null | astro-ph | null | Period-colour (PC) and amplitude-colour (AC) relations at maximum, mean and
minimum light are constructed from a large grid of full amplitude hydrodynamic
models of Cepheids with a composition appropriate for the SMC (Small Magellanic
Cloud). We compare these theoretical relations with those from observations.
The theoretical relations are in general good agreement with their
observational counterparts though there exist some discrepancy for short period
(log [P] < 1) Cepheids. We outline a physical mechanism which can, in
principle, be one factor to explain the observed PC/AC relations for the long
and short period Cepheids in the Galaxy, LMC and SMC. Our explanation relies on
the hydrogen ionization front-photosphere interaction and the way this
interaction changes with pulsation period, pulsation phase and metallicity.
Since the PC relation is connected with the period-luminosity (PL) relation, it
is postulated that such a mechanism can also explain the observed properties of
the PL relation in these three galaxies.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 15:55:52 GMT"
}
] | 2019-08-19T00:00:00 | [
[
"Kanbur",
"S.",
"",
"SUNY-Oswego"
],
[
"Ngeow",
"C.",
"",
"UIUC"
],
[
"Feiden",
"G.",
"",
"SUNY-Oswego"
]
] |
0706.2630 | Mrinal Dasgupta | Mrinal Dasgupta | Parton shower Monte Carlos vs resummed calculations for interjet energy
flow observables | 4 pages, 3 figures, submitted to the proceedings of DIS 07 | null | null | null | hep-ph | null | Parton showers in Monte Carlo event generators reflect to a certain accuracy
our understanding of QCD radiation at all orders. For observables sensitive to
interjet energy flow in well defined regions of phase space, it has been known
for some time that relevant all-order dynamics is substantially more
complicated than that encoded via angular ordering in parton shower algorithms,
even to leading logarithmic accuracy. Here we investigate the extent of the
numerical mismatch between leading logarithmic analytical estimates
(resummation) and parton showers in an effort to better understand the accuracy
of parton showers for such observables.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 15:59:16 GMT"
}
] | 2007-06-19T00:00:00 | [
[
"Dasgupta",
"Mrinal",
""
]
] |
0706.2631 | Claudio De Persis | Claudio De Persis | Minimal data rate stabilization of nonlinear systems over networks with
large delays | 16 pages; references have now been added | null | null | null | math.OC | null | Control systems over networks with a finite data rate can be conveniently
modeled as hybrid (impulsive) systems. For the class of nonlinear systems in
feedfoward form, we design a hybrid controller which guarantees stability, in
spite of the measurement noise due to the quantization, and of an arbitrarily
large delay which affects the communication channel. The rate at which feedback
packets are transmitted from the sensors to the actuators is shown to be
arbitrarily close to the infimal one.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 16:01:11 GMT"
},
{
"version": "v2",
"created": "Tue, 19 Jun 2007 07:12:51 GMT"
}
] | 2007-06-19T00:00:00 | [
[
"De Persis",
"Claudio",
""
]
] |
0706.2632 | Vern Paulsen | Vern I. Paulsen | A Dynamical Systems Approach to the Kadison-Singer Problem | Typos corrected, comments and references added | null | null | AIM 2007-69 | math.OA | null | In these notes we develop a link between the Kadison-Singer problem and
questions about certain dynamical systems. We conjecture that whether or not a
given state has a unique extension is related to certain dynamical properties
of the state. We prove that if any state corresponding to a minimal idempotent
point extends uniquely to the von Neumann algebra of the group, then every
state extends uniquely to the von Neumann algebra of the group. We prove that
if any state arising in the Kadsion-Singer problem has a unique extension, then
the injective envelope of a C*-crossed product algebra associated with the
state necessarily contains the full von Neumann algebra of the group. We prove
that this latter property holds for states arising from rare ultrafilters and
$\delta$-stable ultrafilters, independent, of the group action and also for
states corresponding to non-recurrent points in the corona of the group.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 16:03:14 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Nov 2007 19:17:52 GMT"
}
] | 2007-11-15T00:00:00 | [
[
"Paulsen",
"Vern I.",
""
]
] |
0706.2633 | Alessandro Tanzini | G. Bonelli and A. Tanzini | Topological Gauge Theories on Local Spaces and Black Hole Entropy
Countings | 17 pages | Adv.Theor.Math.Phys.12:6,2008 | null | SISSA 43/2007/EP | hep-th math.AG | null | We study cohomological gauge theories on total spaces of holomorphic line
bundles over complex manifolds and obtain their reduction to the base manifold
by U(1) equivariant localization of the path integral. We exemplify this
general mechanism by proving via exact path integral localization a reduction
for local curves conjectured in hep-th/0411280, relevant to the calculation of
black hole entropy/Gromov-Witten invariants. Agreement with the
four-dimensional gauge theory is recovered by taking into account in the latter
non-trivial contributions coming from one-loop fluctuations determinants at the
boundary of the total space. We also study a class of abelian gauge theories on
Calabi-Yau local surfaces, describing the quantum foam for the A-model,
relevant to the calculation of Donaldson-Thomas invariants.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 16:28:09 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Bonelli",
"G.",
""
],
[
"Tanzini",
"A.",
""
]
] |
0706.2634 | Philip Boalch | Philip Boalch | Quivers and difference Painleve equations | 30 pages, 14 figures. Dedicated to John McKay | null | null | null | math.AG nlin.SI | null | We will describe natural `Lax pairs' for the difference Painleve equations
with affine Weyl symmetry groups of types E6, E7 and E8, showing that they do
indeed arise as symmetries of certain Fuchsian systems of differential
equations.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 17:00:56 GMT"
},
{
"version": "v2",
"created": "Thu, 6 Dec 2007 17:35:24 GMT"
}
] | 2008-10-28T00:00:00 | [
[
"Boalch",
"Philip",
""
]
] |
0706.2635 | Ivan Sadovsky | I. A. Sadovskyy, G. B. Lesovik and G. Blatter | Magnetic flux detection with an Andreev Quantum Dot | 6 pages, 4 figures; minor corrections | Pis'ma v ZhETF 86, 239 (2007) | 10.1134/S0021364007150131 | null | cond-mat.mes-hall cond-mat.supr-con | null | The charge of the subgap states in an Andreev quantum dot (AQD; this is a
quantum dot inserted into a superconducting loop) is very sensitive to the
magnetic flux threading the loop. We study the sensitivity of this device as a
function of its parameters for the limit of a large superconducting gap. In our
analysis, we account for the effects of a weak Coulomb interaction within the
dot. We discuss the suitability of this setup as a device detecting weak
magnetic fields.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 16:46:01 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Sep 2007 16:18:00 GMT"
}
] | 2010-05-19T00:00:00 | [
[
"Sadovskyy",
"I. A.",
""
],
[
"Lesovik",
"G. B.",
""
],
[
"Blatter",
"G.",
""
]
] |
0706.2636 | Andreas Neuenkirch | Andreas Neuenkirch | Optimal pointwise approximation of stochastic differential equations
driven by fractional Brownian motion | 49 pages | null | null | null | math.PR math.NA | null | We study the approximation of stochastic differential equations driven by a
fractional Brownian motion with Hurst parameter $H>1/2$. For the mean-square
error at a single point we derive the optimal rate of convergence that can be
achieved by any approximation method using an equidistant discretization of the
driving fractional Brownian motion. We find that there are mainly two cases:
either the solution can be approximated perfectly or the best possible rate of
convergence is $n^{-H-1/2},$ where $n$ denotes the number of evaluations of the
fractional Brownian motion. In addition, we present an implementable
approximation scheme that obtains the optimal rate of convergence in the latter
case.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 16:51:25 GMT"
}
] | 2007-06-19T00:00:00 | [
[
"Neuenkirch",
"Andreas",
""
]
] |
0706.2637 | F\'abio Zimmer | F. M. Zimmer and S.G. Magalhaes | One-step replica symmetry breaking solution for a highly asymmetric
two-sublattice fermionic Ising spin glass model in a transverse field | 11 pages, 8 figures, accepted for publication in Phys. Rev. B | null | 10.1103/PhysRevB.76.014203 | null | cond-mat.str-el cond-mat.dis-nn | null | The one-step replica symmetry breaking (RSB) is used to study a
two-sublattice fermionic infinite-range Ising spin glass (SG) model in a
transverse field $\Gamma$. The problem is formulated in a Grassmann path
integral formalism within the static approximation. In this model, a parallel
magnetic field $H$ breaks the symmetry of the sublattices. It destroys the
antiferromagnetic (AF) order, but it can favor the nonergodic mixed phase
(SG+AF) characterizing an asymmetric RSB region. In this region,
intra-sublattice disordered interactions $V$ increase the difference between
the RSB solutions of each sublattice. The freezing temperature shows a higher
increase with $H$ when $V$ enhances. A discontinue phase transition from the
replica symmetry (RS) solution to the RSB solution can appear with the presence
of an intra-sublattice ferromagnetic average coupling. The $\Gamma$ field
introduces a quantum spin flip mechanism that suppresses the magnetic orders
leading them to quantum critical points. Results suggest that the quantum
effects are not able to restore the RS solution. However, in the asymmetric RSB
region, $\Gamma$ can produce a stable RS solution at any finite temperature for
a particular sublattice while the other sublattice still presents RSB solution
for the special case in which only the intra-sublattice spins couple with
disordered interactions.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 17:45:34 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Zimmer",
"F. M.",
""
],
[
"Magalhaes",
"S. G.",
""
]
] |
0706.2638 | Wolfgang Angerer P. | Wolfgang P. Angerer | Some applications of the Mellin transform to branching processes | Proof of Theorem 6 revised; minor errors corrected | null | null | null | math.PR | null | We introduce a Mellin transform of functions which live on all of $\bR$ and
discuss its applications to the limiting theory of Bellman-Harris processes,
and specifically Luria-Delbr\"uck processes. More precisely, we calculate the
life-time distribution of particles in a Bellman-Harris process from their
first-generation offspring and limiting distributions, and prove a formula for
the Laplace transform of the distribution of types in a Luria-Delbr\"uck
process in the Mittag-Leffler limit. As a by-product, we show how to easily
derive the (classical) Mellin transforms of certain stable probability
distributions from their Fourier transform.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 18:13:38 GMT"
},
{
"version": "v2",
"created": "Wed, 16 Apr 2008 17:49:54 GMT"
}
] | 2008-04-16T00:00:00 | [
[
"Angerer",
"Wolfgang P.",
""
]
] |
0706.2639 | Robert Loew | Robert Loew, Ulrich Raitzsch, Rolf Heidemann, Vera Bendkowsky, Bjoern
Butscher, Axel Grabowski, and Tilman Pfau | Apparatus for excitation and detection of Rydberg atoms in quantum gases | 10 pages, 9 figures | null | null | null | quant-ph | null | We present and characterize a versatile experimental setup which allows for
excitation and detection of Rydberg atoms in quantum gases. The novel concept
of the setup features two charged particle detectors and eight electrical field
plates inside the vacuum chamber, which allows the detection and manipulation
of Rydberg atoms. The setup presented here is applicable to all atomic species
used in the field of quantum gases. We describe and characterize the production
of Bose-Einstein condensates, the excitation scheme into Rydberg states, the
detection of Rydberg states by field ionization followed by ion detection and
the various electric field configurations provided by the eight field plates.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 18:16:33 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Loew",
"Robert",
""
],
[
"Raitzsch",
"Ulrich",
""
],
[
"Heidemann",
"Rolf",
""
],
[
"Bendkowsky",
"Vera",
""
],
[
"Butscher",
"Bjoern",
""
],
[
"Grabowski",
"Axel",
""
],
[
"Pfau",
"Tilman",
""
]
] |
0706.2640 | Eric Armengaud | E. Armengaud (for the Pierre Auger Collaboration) | Search for large-scale anisotropies with the Auger Observatory | 4 pages, 3 figures. To be published in Proceedings of the 30th
International Cosmic Ray Conference, July 3 - 11, 2007, Merida, Yucatan,
Mexico | null | null | null | astro-ph | null | We use more than two years of data from the Pierre Auger Observatory to
search for anisotropies on large scales in different energy windows. We account
for various systematics in the acceptance, in particular due to the array
growth and weather variations. We present the results of analyses and
consistency checks looking for patterns in the right ascension modulation of
the cosmic ray distribution. No significant anisotropies of this kind are
observed.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 18:34:24 GMT"
}
] | 2019-08-13T00:00:00 | [
[
"Armengaud",
"E.",
"",
"for the Pierre Auger Collaboration"
]
] |
0706.2641 | David d'Enterria | X. Aslanoglou, N. Bakirci, S. Cerci, A. Cyz, D. d'Enterria, E.
Gladysz-Dziadus, L. Gouskos, A. Ivashkin, C. Kalfas, P. Katsas, A. Kuznetsov,
Y. Musienko, A.D. Panagiotou, E. Vlassov | Performance Studies of Prototype II for the CASTOR forward Calorimeter
at the CMS Experiment | 16 pages, 22 figs., submitted to EPJ-C | Eur.Phys.J.C52:495-506,2007 | 10.1140/epjc/s10052-007-0380-x | null | physics.ins-det nucl-ex | null | We present results of the performance of the second prototype of the CASTOR
quartz-tungsten sampling calorimeter, to be installed in the very forward
region of the CMS experiment at the LHC. The energy linearity and resolution,
as well as the spatial resolution of the prototype to electromagnetic and
hadronic showers are studied with E=20-200 GeV electrons, E=20-350 GeV pions,
and E=50,150 GeV muons from beam tests carried out at CERN/SPS in 2004. The
responses of the calorimeter using two different types of photodetectors
(avalanche photodiodes APDs, and photomultiplier tubes PMTs) are compared.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 18:00:32 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Jun 2007 12:12:01 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Aslanoglou",
"X.",
""
],
[
"Bakirci",
"N.",
""
],
[
"Cerci",
"S.",
""
],
[
"Cyz",
"A.",
""
],
[
"d'Enterria",
"D.",
""
],
[
"Gladysz-Dziadus",
"E.",
""
],
[
"Gouskos",
"L.",
""
],
[
"Ivashkin",
"A.",
""
],
[
"Kalfas",
"C.",
""
],
[
"Katsas",
"P.",
""
],
[
"Kuznetsov",
"A.",
""
],
[
"Musienko",
"Y.",
""
],
[
"Panagiotou",
"A. D.",
""
],
[
"Vlassov",
"E.",
""
]
] |
0706.2642 | Victor Guillemin | Zuoqin Wang | The twisted Mellin transform | 10 pages | null | null | null | math.CO | null | The "twisted Mellin transform" is a slightly modified version of the usual
classical Mellin transform on $L^2(\mathbb R)$. In this short note we
investigate some of its basic properties. From the point of views of
combinatorics one of its most important interesting properties is that it
intertwines the differential operator, $df/dx$, with its finite difference
analogue, $\nabla f= f(x)-f(x-1)$. From the point of view of analysis one of
its most important properties is that it describes the asymptotics of one
dimensional quantum states in Bargmann quantization.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 19:10:58 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 16:18:22 GMT"
}
] | 2007-06-27T00:00:00 | [
[
"Wang",
"Zuoqin",
""
]
] |
0706.2643 | Lorenzo Perrone Dr | Lorenzo Perrone (for the the Pierre Auger Collaboration) | Measurement of the UHECR energy spectrum from hybrid data of the Pierre
Auger Observatory | To appear in the proceedings of 30th International Cosmic Ray
Conference (ICRC 2007), Merida, Yucatan, Mexico, 3-11 Jul 2007 - 4pp | null | null | null | astro-ph | null | More than two years of fluorescence detector data collected in coincidence
with at least one station of the surface detector array (``hybrid data'') are
used to measure the flux and energy spectrum of cosmic rays above about
10$^{18}$ eV. The hybrid measurement extends towards lower energies the
spectrum measured with the surface detector data only, and provides a
cross-check with an independent data set. The determination of the fluorescence
detector aperture and of its live-time, which is the major aspect of this
measurement, is illustrated in detail. Our current estimate of the
corresponding systematic uncertainties are given.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 18:43:15 GMT"
}
] | 2019-08-13T00:00:00 | [
[
"Perrone",
"Lorenzo",
"",
"for the the Pierre Auger Collaboration"
]
] |
0706.2644 | Vern Paulsen | Vern I. Paulsen, Mrinal Raghupathi | Some new equivalences of Anderson's paving conjectures | Typos corrected, references added | null | null | AIM 2007-70 | math.OA | null | Anderson's paving conjectures are known to be equivalent to the
Kadison-Singer problem. We prove some new equivalences of Anderson's
conjectures that require the paving of smaller sets of matrices. We prove that
if the strictly upper triangular operatorss are pavable, then every 0 diagonal
operator is pavable. This result follows from a new paving condition for
positive operators. In addition, we prove that if the upper triangular Toeplitz
operators are paveable, then all Toeplitz operators are paveable.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 18:50:15 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Nov 2007 19:36:13 GMT"
}
] | 2007-11-15T00:00:00 | [
[
"Paulsen",
"Vern I.",
""
],
[
"Raghupathi",
"Mrinal",
""
]
] |
0706.2645 | Andrew Raich | Andrew S. Raich, Emil J. Straube | Compactness of the Complex Green Operator | 17 pages. We added an appendix, fixed the proof of a main theorem,
and revised the statement of another theorem. Also, we fixed some other typos | Math. Res. Lett. 15 (2008), no. 4, 761--778 | null | null | math.CV math.AP | null | Let $\Omega\subset\C^n$ be a bounded smooth pseudoconvex domain. We show that
compactness of the complex Green operator $G_{q}$ on $(0,q)$-forms on $b\Omega$
implies compactness of the $\bar{\partial}$-Neumann operator $N_{q}$ on
$\Omega$. We prove that if $1 \leq q \leq n-2$ and $b\Omega$ satisfies $(P_q)$
and $(P_{n-q-1})$, then $G_{q}$ is a compact operator (and so is $G_{n-1-q}$).
Our method relies on a jump type formula to represent forms on the boundary,
and we prove an auxiliary compactness result for an `annulus' between two
pseudoconvex domains. Our results, combined with the known characterization of
compactness in the $\bar{\partial}$-Neumann problem on locally convexifiable
domains, yield the corresponding characterization of compactness of the complex
Green operator(s) on these domains.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 18:52:18 GMT"
},
{
"version": "v2",
"created": "Tue, 19 Jun 2007 01:11:31 GMT"
},
{
"version": "v3",
"created": "Thu, 18 Oct 2007 12:59:19 GMT"
}
] | 2009-03-24T00:00:00 | [
[
"Raich",
"Andrew S.",
""
],
[
"Straube",
"Emil J.",
""
]
] |
0706.2646 | Terence C. Tao | Terence Tao | A quantitative version of the Besicovitch projection theorem via
multiscale analysis | 30 pages, 6 figures. Submitted, J. Lond. Math. Soc. Some revisions
based on initial referee report | null | 10.1112/plms/pdn037 | null | math.CA math.MG | null | By using a multiscale analysis, we establish quantitative versions of the
Besicovitch projection theorem (almost every projection of a purely
unrectifiable set in the plane of finite length has measure zero) and a
standard companion result, namely that any planar set with at least two
projections of measure zero is purely unrectifiable. We illustrate these
results by providing an explicit (but weak) upper bound on the average
projection of the $n^{th}$ generation of a product Cantor set.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 19:00:42 GMT"
},
{
"version": "v2",
"created": "Thu, 15 May 2008 00:19:38 GMT"
}
] | 2014-02-26T00:00:00 | [
[
"Tao",
"Terence",
""
]
] |
0706.2647 | Kei Funano | Kei Funano | A note for Gromov's distance functions on the space of mm-spaces | 21pages | null | null | null | math.MG | null | This is just a note for \cite[Chapter$3{1/2}_+$]{gromov}. Maybe this note is
obvious for a reader who knows metric geometry. I wish that someone study
further in this direction.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 19:03:31 GMT"
}
] | 2007-06-19T00:00:00 | [
[
"Funano",
"Kei",
""
]
] |
0706.2648 | Huayi Chen | Huayi Chen (CMLS-EcolePolytechnique) | Harder-Narasimhan categories | null | null | null | null | math.AG math.CT | null | We propose a generalization of Quillen's exact category -- arithmetic exact
category and we discuss conditions on such categories under which one can
establish the notion of Harder-Narasimhan filtrations and Harder-Narsimhan
polygons. Furthermore, we show the functoriality of Harder-Narasimhan
filtrations (indexed by $\mathbb R$), which can not be stated in the classical
setting of Harder and Narasimhan's formalism.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 19:06:47 GMT"
},
{
"version": "v2",
"created": "Sat, 30 Jun 2007 05:30:13 GMT"
}
] | 2007-07-02T00:00:00 | [
[
"Chen",
"Huayi",
"",
"CMLS-EcolePolytechnique"
]
] |
0706.2649 | Huayi Chen | Huayi Chen (CMLS-EcolePolytechnique) | Convergence of Harder-Narasimhan polygons | null | null | null | null | math.AG | null | We establish in this article convergence results of normalized
Harder-Narasimhan polygons both in geometric and in arithmetic frameworks by
introducing the Harder-Narasimhan filtration indexed by $\mathbb R$ and the
associated Borel probability measure.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 19:07:29 GMT"
}
] | 2007-06-19T00:00:00 | [
[
"Chen",
"Huayi",
"",
"CMLS-EcolePolytechnique"
]
] |
0706.2650 | Ping Ao | P Ao | Comment on "Magnus force and acoustic Stewart-Tolman effect in type-II
superconductors, by Fil et al | latex 4 pages | null | null | null | cond-mat.supr-con cond-mat.stat-mech | null | Fil {\it et al.} has proposed an interesting experimental method to
investigate vortex dynamics. Some preliminary results have been obtained. In
this comment I discuss a few missing but strongly related theoretical models
and experiments on Hall anomaly and Magnus force. I conclude that those missing
literature can enhance the value of novel experimental method proposed in the
commented 2006 Europhysics Letters by Fil {\it et al.}.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 19:15:26 GMT"
}
] | 2007-06-19T00:00:00 | [
[
"Ao",
"P",
""
]
] |
0706.2651 | Georg Hoffstaetter | Brandon Buckley and Georg H. Hoffstaetter | Transverse emittance dilution due to coupler kicks in linear
accelerators | null | Phys.Rev.STAccel.Beams10:111002,2007 | 10.1103/PhysRevSTAB.10.111002 | null | physics.acc-ph physics.comp-ph | null | One of the main concerns in the design of low emittance linear accelerators
(linacs) is the preservation of beam emittance. Here we discuss one possible
source of emittance dilution, the coupler kick, due to transverse
electromagnetic fields in the accelerating cavities of the linac caused by the
power coupler geometry. In addition to emittance growth, the coupler kick also
produces orbit distortions. It is common wisdom that emittance growth from
coupler kicks can be strongly reduced by using two couplers per cavity mounted
opposite each other or by having the couplers of successive cavities
alternation from above to below the beam pipe so as to cancel each individual
kick. We therefore analyze consequences of alternate coupler placements.
We show here that for sufficiently large Q values, alternating the coupler
location from before to after the cavity leads to a cancellation of the orbit
distortion but not of the emittance growth, whereas alternating the coupler
location from before and above to behind and below the cavity cancels the
emittance growth but not the orbit distortion. These compensations hold even
when each cavity is individually detuned, e.g. by microphonics. Another
effective method for reducing coupler kicks that is studied is the optimization
of the phase of the coupler kick. This technique is independent of the coupler
geometry but relies on operating on crest. A final technique studied is
symmetrization of the cavity geometry in the coupler region with the addition
of a stub opposite the coupler, which reduces the amplitude of the off axis
fields and is thus effective for off crest acceleration as well.
We show applications of these techniques to the energy recovery linac (ERL)
planned at Cornell University.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 20:49:24 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Jun 2007 02:30:21 GMT"
},
{
"version": "v3",
"created": "Thu, 6 Sep 2007 00:11:05 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Buckley",
"Brandon",
""
],
[
"Hoffstaetter",
"Georg H.",
""
]
] |
0706.2652 | Charles Bradley | C.K. Bradley, R.I. Hynes, A.K.H. Kong, C.A. Haswell, J. Casares, E.
Gallo | The Spectrum of the Black Hole X-ray Nova V404 Cygni in Quiescence as
Measured by XMM-Newton | 6 pages, 7 figures, ApJ accepted | Astrophys.J.667:427-432,2007 | 10.1086/520323 | null | astro-ph | null | We present XMM observations of the black hole X-ray nova V404 Cygni in
quiescence. Its quiescent spectrum can be best fitted by a simple power-law
with slope 2. The spectra are consistent with that expected for the
advection-dominated accretion flow (ADAF). V404 Cyg was roughly equal in
luminosity compared to the previous observation of Chandra. We see variability
of a factor of 4 during the observation. We find no evidence for the presence
of fluorescent or H-like/He-like iron emission, with upper limits of 52 eV and
110 eV respectively. The limit on the fluorescent emission is improved by a
factor of 15 over the previous estimate, and the restriction on H-like/He-like
emission is lower than predicted from models by a factor of roughly 2.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 20:31:13 GMT"
}
] | 2011-02-11T00:00:00 | [
[
"Bradley",
"C. K.",
""
],
[
"Hynes",
"R. I.",
""
],
[
"Kong",
"A. K. H.",
""
],
[
"Haswell",
"C. A.",
""
],
[
"Casares",
"J.",
""
],
[
"Gallo",
"E.",
""
]
] |
0706.2653 | Pascal Oesch | P. A. Oesch (1), M. Stiavelli (2), C. M. Carollo (1), L. E. Bergeron
(2), A. M. Koekemoer (2), R. A. Lucas (2), C. M. Pavlovsky (2), M. Trenti
(2), S. J. Lilly (1), S. V. W. Beckwith (2), T. Dahlen (2), H. C. Ferguson
(2), J. P. Gardner (3), C. Lacey (4), B. Mobasher (2), N. Panagia (2,5,6),
H.-W. Rix (7) ((1) Department of Astrophysics, ETH Zurich, (2) Space
Telescope Science Institute, (3) NASA's GSFC, (4) Institute for Computational
Cosmology, University of Durham, (5) INAF- Osservatorio Astrofisico di
Catania, (6) Supernova Ltd., (7) Max-Planck-Institute for Astronomy) | The UDF05 Follow-up of the HUDF: I. The Faint-End Slope of the
Lyman-Break Galaxy Population at z~5 | 16 pages, 11 figures, small changes to match version accepted for
publication in ApJ | null | 10.1086/522423 | null | astro-ph | null | We present the UDF05 project, a HST Large Program of deep ACS (F606W, F775W,
F850LP) and NICMOS (F110W, F160W) imaging of three fields, two of which
coincide with the NICP1-4 NICMOS parallel observations of the Hubble Ultra Deep
Field (HUDF). In this first paper we use the ACS data for the NICP12 field, as
well as the original HUDF ACS data, to measure the UV Luminosity Function (LF)
of z~5 Lyman Break Galaxies (LBGs) down to very faint levels. Specifically,
based on a V-i, i-z selection criterion, we identify a sample of 101 and 133
candidate z~5 galaxies down to z_{850}=28.5 and 29.25 magnitudes in the NICP12
and in the HUDF fields, respectively. Using an extensive set of Monte Carlo
simulations we derive corrections for observational biases and selection
effects, and construct the rest-frame 1400 A LBG LF over the range
M_{1400}=[-21.4, -17.1], i.e. down to ~0.04 L* at z~5, and complement it with
data from the Subaru Deep Field (SDF) from Yoshida et al. (2006) to extend it
to the brighter end (M_{1400}>-22.2). We show that: (i) Different assumptions
regarding the SED distribution of the LBG population, dust properties and
intergalactic absorption result in a 25% variation in the number density of
LBGs at z~5; (ii) Under consistent assumptions for dust properties and
intergalactic absorption, the HUDF is about 30% under-dense in z~5 LBGs
relative to the NICP12 field, a variation which is well explained by cosmic
variance; (iii) The faint-end slope of the LF is independent of the specific
assumptions for the input physical parameters, and has a value of alpha ~ -1.6,
similar to the faint-end slope of the LF that has been measured for LBGs at z~3
and z~6.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 20:13:27 GMT"
},
{
"version": "v2",
"created": "Fri, 17 Aug 2007 10:21:56 GMT"
}
] | 2007-12-20T00:00:00 | [
[
"Oesch",
"P. A.",
""
],
[
"Stiavelli",
"M.",
""
],
[
"Carollo",
"C. M.",
""
],
[
"Bergeron",
"L. E.",
""
],
[
"Koekemoer",
"A. M.",
""
],
[
"Lucas",
"R. A.",
""
],
[
"Pavlovsky",
"C. M.",
""
],
[
"Trenti",
"M.",
""
],
[
"Lilly",
"S. J.",
""
],
[
"Beckwith",
"S. V. W.",
""
],
[
"Dahlen",
"T.",
""
],
[
"Ferguson",
"H. C.",
""
],
[
"Gardner",
"J. P.",
""
],
[
"Lacey",
"C.",
""
],
[
"Mobasher",
"B.",
""
],
[
"Panagia",
"N.",
""
],
[
"Rix",
"H. -W.",
""
]
] |
0706.2654 | Ishwaree Neupane | Ishwaree P. Neupane | Reconstructing a model of quintessential inflation | 18 pages, 7 figures; added refs, published version | Class.Quant.Grav.25:125013,2008 | 10.1088/0264-9381/25/12/125013 | null | hep-th astro-ph gr-qc hep-ph | null | We present an explicit cosmological model where inflation and dark energy
both could arise from the dynamics of the same scalar field. We present our
discussion in the framework where the inflaton field $\phi$ attains a nearly
constant velocity $m_P^{-1} |d\phi/dN|\equiv \alpha+\beta \exp(\beta N)$ (where
$N\equiv \ln a$ is the e-folding time) during inflation. We show that the model
with $|\alpha|<0.25$ and $\beta<0$ can easily satisfy inflationary constraints,
including the spectral index of scalar fluctuations ($n_s=0.96\pm 0.013$),
tensor-to-scalar ratio ($r<0.28$) and also the bound imposed on $\Omega_\phi$
during the nucleosynthesis epoch ($\Omega_\phi (1 {\rm MeV})<0.1$). In our
construction, the scalar field potential always scales proportionally to the
square of the Hubble expansion rate. One may thereby account for the two vastly
different energy scales associated with the Hubble parameters at early and late
epochs. The inflaton energy could also produce an observationally significant
effective dark energy at a late epoch without violating local gravity tests.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 08:03:06 GMT"
},
{
"version": "v2",
"created": "Wed, 12 Sep 2007 00:41:20 GMT"
},
{
"version": "v3",
"created": "Thu, 29 Nov 2007 16:50:32 GMT"
},
{
"version": "v4",
"created": "Sat, 31 May 2008 22:06:16 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Neupane",
"Ishwaree P.",
""
]
] |
0706.2655 | Spyros Avramis | Spyros D. Avramis, Konstadinos Sfetsos, Konstadinos Siampos | Stability of string configurations dual to quarkonium states in AdS/CFT | 41 pages, 16 figures; v2: minor typos corrected, version to appear in
Nucl. Phys. B | Nucl.Phys.B793:1-33,2008 | 10.1016/j.nuclphysb.2007.09.025 | null | hep-th | null | We extend our earlier work, regarding the perturbative stability of string
configurations used for computing the interaction potential of heavy quarks
within the gauge/gravity correspondence, to cover a more general class of
gravity duals. We provide results, mostly based on analytic methods and
corroborated by numerical calculations, which apply to strings in a general
class of backgrounds that encompass boosted, spinning and marginally-deformed
D3-brane backgrounds. For the case of spinning branes we demonstrate in a few
examples that perturbative stability of strings requires strong conditions
complementing those following by thermodynamic stability of the dual field
theories. For marginally-deformed backgrounds, we find that even in the
conformal case stability may require an upper value for the imaginary part of
the deformation parameter, whereas in regions of the Coulomb branch where there
exists linear confinement we find that there exist stable string configurations
for certain ranges of values of this parameter. We finally discuss the case of
open strings with fixed endpoints propagating in Rindler space, which turns out
to have an exact classical-mechanical analog.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 19:07:10 GMT"
},
{
"version": "v2",
"created": "Mon, 29 Oct 2007 01:18:38 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Avramis",
"Spyros D.",
""
],
[
"Sfetsos",
"Konstadinos",
""
],
[
"Siampos",
"Konstadinos",
""
]
] |
0706.2656 | N. Bouche | N. Bouche, G. Cresci, R. Davies, F. Eisenhauer, N. M. Forster
Schreiber, R. Genzel, S. Gillessen, M. Lehnert, D. Lutz, N. Nesvadba, K. L.
Shapiro, A. Sternberg, L. J. Tacconi, A. Verma, A. Cimatti, E. Daddi, A.
Renzini, D. K. Erb, A. Shapley, C. C. Steidel | Dynamical Properties of z~2 Star Forming Galaxies and a Universal Star
Formation Relation | 14 pages, 3 figures, accepted for publication in ApJ, minor typos
corrected | null | 10.1086/522221 | null | astro-ph | null | We present the first comparison of the dynamical properties of different
samples of z~1.4-3.4 star forming galaxies from spatially resolved imaging
spectroscopy from SINFONI/VLT integral field spectroscopy and IRAM CO
millimeter interferometry. Our samples include 16 rest-frame UV-selected, 16
rest-frame optically-selected and 13 submillimeter galaxies (SMGs). We find
that restframe UV- and optically bright (K<20) z~2 star forming galaxies are
dynamically similar, and follow the same velocity-size relation as disk
galaxies at z~0. In the theoretical framework of rotating disks forming from
dissipative collapse in dark matter halos, the two samples require a spin
parameter ranging from 0.06 to 0.2. In contrast bright SMGs have larger
velocity widths and are much more compact. Hence, SMGs have lower angular
momenta and higher matter densities than either of the UV- or optically
selected populations. This indicates that dissipative major mergers may
dominate the SMGs population, resulting in early spheroids, and that the
majority of UV/optically bright galaxies have evolved less violently [...].
These early disks may later evolve into spheroids via disk instabilities or
mergers. Because of their small sizes and large densities, SMGs lie at the high
surface density end of a universal (out to z=2.5) "Schmidt-Kennicutt" relation
between gas surface density and star formation rate surface density with a
slope of ~1.7.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 07:33:06 GMT"
},
{
"version": "v2",
"created": "Mon, 15 Oct 2007 12:23:01 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bouche",
"N.",
""
],
[
"Cresci",
"G.",
""
],
[
"Davies",
"R.",
""
],
[
"Eisenhauer",
"F.",
""
],
[
"Schreiber",
"N. M. Forster",
""
],
[
"Genzel",
"R.",
""
],
[
"Gillessen",
"S.",
""
],
[
"Lehnert",
"M.",
""
],
[
"Lutz",
"D.",
""
],
[
"Nesvadba",
"N.",
""
],
[
"Shapiro",
"K. L.",
""
],
[
"Sternberg",
"A.",
""
],
[
"Tacconi",
"L. J.",
""
],
[
"Verma",
"A.",
""
],
[
"Cimatti",
"A.",
""
],
[
"Daddi",
"E.",
""
],
[
"Renzini",
"A.",
""
],
[
"Erb",
"D. K.",
""
],
[
"Shapley",
"A.",
""
],
[
"Steidel",
"C. C.",
""
]
] |
0706.2657 | Erhai Zhao | Erhai Zhao, Arun Paramekanti (University of Toronto) | Self-consistent slave rotor mean field theory for strongly correlated
systems | final version, to appear in PRB; added reference to latest quantum
oscillation experiments on YBa_2Cu_4O_8 | Phys. Rev. B 76, 195101 (2007) | 10.1103/PhysRevB.76.195101 | null | cond-mat.str-el cond-mat.supr-con | null | Building on work by Florens and Georges, we formulate and study a
self-consistent slave rotor mean field theory for strongly correlated systems.
This approach views the electron, in the strong correlation regime, as a
composite of a neutral spinon and a charged rotor field. We solve the coupled
spinon-rotor model self-consistently using a cluster mean field theory for the
rotors and various ansatzes for the spinon ground state. We illustrate this
approach with a number of examples relevant to ongoing experiments in strongly
correlated electronic systems such as: (i) the phase diagram of the isotropic
triangular lattice organic Mott insulators, (ii) quasiparticle excitations and
tunneling asymmetry in the weakly doped cuprate superconductors, and (iii) the
cyclotron mass of carriers in commensurate spin-density wave and U(1) staggered
flux (or d-density wave) normal states of the underdoped cuprates. We compare
the estimated cyclotron mass with results from recent quantum oscillation
experiments on ortho-II YBCO by N. Doiron-Leyraud et al (Nature 447, 565
[2007]) which appear to find hole pockets in the magnetic field induced normal
state. We comment on the relation of this normal ground state to Fermi arcs
seen in photoemission experiments above Tc. This slave rotor mean field theory
can be generalized to study inhomogeneous states and strongly interacting
models relevant to ultracold atoms in optical lattices.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 20:13:06 GMT"
},
{
"version": "v2",
"created": "Tue, 19 Jun 2007 21:46:22 GMT"
},
{
"version": "v3",
"created": "Thu, 19 Jul 2007 18:16:41 GMT"
},
{
"version": "v4",
"created": "Thu, 19 Jul 2007 21:28:36 GMT"
},
{
"version": "v5",
"created": "Mon, 27 Aug 2007 21:23:50 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Zhao",
"Erhai",
"",
"University of Toronto"
],
[
"Paramekanti",
"Arun",
"",
"University of Toronto"
]
] |
0706.2658 | Pertti Hakonen | T. Tsuneta, P. Virtanen, F. Wu, T. Wang, T.T. Heikkil\"a, and P.J.
Hakonen | Local and Non-local Shot Noise in Multiwalled Carbon Nanotubes | 4 pages, 4 figures | EPL 85, 37004 (2009) | 10.1209/0295-5075/85/37004 | null | cond-mat.mes-hall | null | We have investigated shot noise in multiterminal, diffusive multiwalled
carbon nanotubes (MWNTs) at 4.2 K over the frequency f = 600 - 850 MHz.
Quantitative comparison of our data to semiclassical theory, based on
non-equilibrium distribution functions, indicates that a major part of the
noise is caused by a non-equilibrium state imposed by the contacts. Our data
exhibits non-local shot noise across weakly transmitting contacts while a
low-impedance contact eliminates such noise almost fully. We obtain F_{tube}<
0.03 for the intrinsic Fano factor of our MWNTs.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 20:26:16 GMT"
}
] | 2010-06-30T00:00:00 | [
[
"Tsuneta",
"T.",
""
],
[
"Virtanen",
"P.",
""
],
[
"Wu",
"F.",
""
],
[
"Wang",
"T.",
""
],
[
"Heikkilä",
"T. T.",
""
],
[
"Hakonen",
"P. J.",
""
]
] |
0706.2659 | Vincenzo Chilla | Vincenzo Chilla | Selection and identity rules for subductions of type A quantum
Iwahori-Hecke algebras | 17 pages, no figures, 1 table. Bibliographic references added.
Accepted for publication on J. Math. Phys | J.Math.Phys.48:113515,2007 | 10.1063/1.2812422 | null | math-ph hep-th math.MP | null | This paper is concerned with the subduction problem of type A quantum
Iwahori-Hecke algebras $\mathbb{C} \mathbf{H}(\mathfrak{S}_f,q^2)$ with a real
deformation parameter $q$, i.e. the problem of decomposing irreducible
representations of such algebras as direct sum of irreducible representations
of the subalgebras $\mathbb{C}\mathbf{H}(\mathfrak{S}_{f_1}, q^2) \times
\mathbb{C}\mathbf{H}(\mathfrak{S}_{f_2}, q^2)$, with $f_1 + f_2 = f$. After
giving a suitable combinatorial description for the subduction issue, we
provide a selection rule, based on the Richardson-Littlewood criterion, which
allows to determine the vanishing coupling coefficients between standard basis
vectors for such representations, and we also present an equivariance condition
for the subduction coefficients. Such results extend those ones corresponding
to the subduction problem in symmetric group algebras $\mathbb{C}\mathfrak{S}_f
\downarrow \mathbb{C}\mathfrak{S}_{f_1} \times \mathbb{C} \mathfrak{S}_{f_2}$
which are obtained by $q$ approaching the value 1.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 20:30:08 GMT"
},
{
"version": "v2",
"created": "Fri, 26 Oct 2007 20:44:14 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Chilla",
"Vincenzo",
""
]
] |
0706.2660 | Eun-Ah Kim | Suk Bum Chung, Hendrik Bluhm, Eun-Ah Kim | Stability of half-quantum vorticies in p_x+ip_y superconductors | 4 pages, 2 figures. The version accepted for publication in Phys.
Rev. Lett. Compared to version 1, the revised version is shorter and one
reference was added | Phys. Rev. Lett., vol 99, 197002 (2007) | 10.1103/PhysRevLett.99.197002 | null | cond-mat.supr-con cond-mat.str-el | null | We consider the stability conditions for half-quantum vortices in quasi two
dimensional $p_x+ip_y$ superconductor (such as ${\rm Sr_2 RuO_4}$ is believed
to be) through energetics calculations. Although the predicted exotic nature of
these excitations have recently attracted much attention but they have not been
observed yet. We pay particular attention to the fact that an isolated half
quantum vortex has a divergent energy cost in the bulk due to the associated
{\it unscreened} spin current, which requires two half-quantum vortices with
opposite spin winding to pair. We show that the stability of such a pair in
bulk is enhanced when the ratio of spin superfluid density to superfluid
density $\rho_{{\rm sp}}/\rho_{\rm s}$ is small. As a step towards stabilizing
and observing these exotic excitations, we propose using various mesoscopic
geometries. We find that certain mesoscopic geometries can selectively allow
only single half-quantum vortices to enter the sample for small $\rho_{{\rm
sp}}/\rho_{\rm s}$.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 20:30:21 GMT"
},
{
"version": "v2",
"created": "Wed, 19 Sep 2007 05:50:29 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Chung",
"Suk Bum",
""
],
[
"Bluhm",
"Hendrik",
""
],
[
"Kim",
"Eun-Ah",
""
]
] |
0706.2661 | Nicholas Harrigan | Nicholas Harrigan and Robert W. Spekkens | Einstein, incompleteness, and the epistemic view of quantum states | 18 pages, 8 figures, 1 recipe for cupcakes; comments welcome | Found. Phys. 40, 125 (2010) | 10.1007/s10701-009-9347-0 | null | quant-ph | null | Does the quantum state represent reality or our knowledge of reality? In
making this distinction precise, we are led to a novel classification of hidden
variable models of quantum theory. Indeed, representatives of each class can be
found among existing constructions for two-dimensional Hilbert spaces. Our
approach also provides a fruitful new perspective on arguments for the
nonlocality and incompleteness of quantum theory. Specifically, we show that
for models wherein the quantum state has the status of something real, the
failure of locality can be established through an argument considerably more
straightforward than Bell's theorem. The historical significance of this result
becomes evident when one recognizes that the same reasoning is present in
Einstein's preferred argument for incompleteness, which dates back to 1935.
This fact suggests that Einstein was seeking not just any completion of quantum
theory, but one wherein quantum states are solely representative of our
knowledge. Our hypothesis is supported by an analysis of Einstein's attempts to
clarify his views on quantum theory and the circumstance of his otherwise
puzzling abandonment of an even simpler argument for incompleteness from 1927.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 22:02:12 GMT"
}
] | 2010-03-30T00:00:00 | [
[
"Harrigan",
"Nicholas",
""
],
[
"Spekkens",
"Robert W.",
""
]
] |
0706.2662 | Benjamin Davidovitch | Benny Davidovitch (Harvard, UMass), Michael J. Aziz (Harvard), Michael
P. Brenner (Harvard) | On the stabilization of ion sputtered surfaces | null | null | 10.1103/PhysRevB.76.205420 | null | cond-mat.mtrl-sci cond-mat.other | null | The classical theory of ion beam sputtering predicts the instability of a
flat surface to uniform ion irradiation at any incidence angle. We relax the
assumption of the classical theory that the average surface erosion rate is
determined by a Gaussian response function representing the effect of the
collision cascade and consider the surface dynamics for other
physically-motivated response functions. We show that although instability of
flat surfaces at any beam angle results from all Gaussian and a wide class of
non-Gaussian erosive response functions, there exist classes of modifications
to the response that can have a dramatic effect. In contrast to the classical
theory, these types of response render the flat surface linearly stable, while
imperceptibly modifying the predicted sputter yield vs. incidence angle. We
discuss the possibility that such corrections underlie recent reports of a
``window of stability'' of ion-bombarded surfaces at a range of beam angles for
certain ion and surface types, and describe some characteristic aspects of
pattern evolution near the transition from unstable to stable dynamics. We
point out that careful analysis of the transition regime may provide valuable
tests for the consistency of any theory of pattern formation on ion sputtered
surfaces.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 20:57:02 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Davidovitch",
"Benny",
"",
"Harvard, UMass"
],
[
"Aziz",
"Michael J.",
"",
"Harvard"
],
[
"Brenner",
"Michael P.",
"",
"Harvard"
]
] |
0706.2663 | Terrance Gaetz | Terrance J. Gaetz, William P. Blair, John P. Hughes, P. Frank Winkler,
Knox S. Long, Thomas G. Pannuti, Benjamin Williams, Richard J. Edgar, Parviz
Ghavamian, Paul P. Plucinsky, Manami Sasaki, Robert P. Kirshner, Miguel
Avillez, and Dieter Breitschwerdt | Chandra ACIS Survey of M33 (ChASeM33): X-ray Imaging Spectroscopy of
M33SNR21, the Brightest X-ray Supernova Remnant in M33 | 27 pages, 6 figures (3 color). ApJ (in press) | Astrophys.J.663:234-243,2007 | 10.1086/518397 | null | astro-ph | null | We present and interpret new X-ray data for M33SNR21, the brightest X-ray
supernova remnant (SNR) in M33. The SNR is in seen projection against (and
appears to be interacting with) the bright HII region NGC592. Data for this
source were obtained as part of the Chandra ACIS Survey of M33 (ChASeM33) Very
Large Project. The nearly on-axis Chandra data resolve the SNR into a ~5"
diameter (20 pc at our assumed M33 distance of 817+/-58 kpc) slightly
elliptical shell. The shell is brighter in the east, which suggests that it is
encountering higher density material in that direction. The optical emission is
coextensive with the X-ray shell in the north, but extends well beyond the
X-ray rim in the southwest. Modeling the X-ray spectrum with an absorbed sedov
model yields a shock temperature of 0.46(+0.01,-0.02) keV, an ionization
timescale of n_e t = $2.1 (+0.2,-0.3) \times 10^{12}$ cm$^{-3}$ s, and
half-solar abundances (0.45 (+0.12, -0.09)). Assuming Sedov dynamics gives an
average preshock H density of 1.7 +/- 0.3 cm$^{-3}$. The dynamical age estimate
is 6500 +/- 600 yr, while the best fit $n_e t$ value and derived $n_e$ gives
8200 +/- 1700 yr; the weighted mean of the age estimates is 7600 +/- 600 yr. We
estimate an X-ray luminosity (0.25-4.5 keV) of (1.2 +/- 0.2) times $10^{37}$
ergs s$^{-1}$ (absorbed), and (1.7 +/- 0.3) times $10^{37}$ ergs s$^{-1}$
(unabsorbed), in good agreement with the recent XMM-Newton determination. No
significant excess hard emission was detected; the luminosity $\le 1.2\times
10^{35}$ ergs s$^{-1}$ (2-8 keV) for any hard point source.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 21:12:41 GMT"
}
] | 2011-02-11T00:00:00 | [
[
"Gaetz",
"Terrance J.",
""
],
[
"Blair",
"William P.",
""
],
[
"Hughes",
"John P.",
""
],
[
"Winkler",
"P. Frank",
""
],
[
"Long",
"Knox S.",
""
],
[
"Pannuti",
"Thomas G.",
""
],
[
"Williams",
"Benjamin",
""
],
[
"Edgar",
"Richard J.",
""
],
[
"Ghavamian",
"Parviz",
""
],
[
"Plucinsky",
"Paul P.",
""
],
[
"Sasaki",
"Manami",
""
],
[
"Kirshner",
"Robert P.",
""
],
[
"Avillez",
"Miguel",
""
],
[
"Breitschwerdt",
"Dieter",
""
]
] |
0706.2664 | Eero Saksman | Eva A. Gallardo-Guti\'errez, Maria J. Gonz\'alez, Pekka Nieminen and
Eero Saksman | On the connected component of compact composition operators on the Hardy
space | 16 pages | null | null | null | math.FA math.CV | null | We show that there exist non-compact composition operators in the connected
component of the compact ones on the classical Hardy space $H^2$ on the unit
disc. This answers a question posed by Shapiro and Sundberg in 1990. We also
establish an improved version of a theorem of MacCluer, giving a lower bound
for the essential norm of a difference of composition operators in terms of the
angular derivatives of their symbols. As a main tool we use Aleksandrov-Clark
measures.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 20:56:11 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Gallardo-Gutiérrez",
"Eva A.",
""
],
[
"González",
"Maria J.",
""
],
[
"Nieminen",
"Pekka",
""
],
[
"Saksman",
"Eero",
""
]
] |
0706.2665 | Rogerio Rosenfeld | Hiroshi de Sandes and Rogerio Rosenfeld | Higgs Pair Production at the LHC in Models with Universal Extra
Dimensions | 10 pages, 6 figures. LHC cross section computed, 2 new figures | Phys.Lett.B659:323-327,2008 | 10.1016/j.physletb.2007.10.076 | null | hep-ph | null | In this letter we study the process of gluon fusion into a pair of Higgs
bosons in a model with one universal extra dimension. We find that the
contributions from the extra top quark Kaluza-Klein excitations lead to a Higgs
pair production cross section at the LHC that can be significantly altered
compared to the Standard Model value for small values of the compactification
scale.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 20:58:49 GMT"
},
{
"version": "v2",
"created": "Fri, 3 Aug 2007 21:07:59 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"de Sandes",
"Hiroshi",
""
],
[
"Rosenfeld",
"Rogerio",
""
]
] |
0706.2666 | Ivan Cheltsov | Ivan Cheltsov | On singular cubic surfaces | 17 pages | null | null | null | math.AG math.DG | null | We study global log canonical thresholds of cubic surfaces with canonical
singularities, and we prove the existence of a Kahler-Einstein metric on two
singular cubic surfaces.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 12:28:43 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Cheltsov",
"Ivan",
""
]
] |
0706.2667 | Katarzyna Kowalik | Katarzyna Kowalik (for the STAR collaboration) | Longitudinal double spin asymmetry in jet production at STAR | 4 pages, 1 figure | null | null | LBNL-61701 Conf | hep-ex | null | We present recent measurements of the longitudinal double-spin asymmetry A_LL
for the inclusive production of jets at midrapidity in polarized proton-proton
collisions at sqrt(s)=200GeV. The data amount to an integrated luminosity of
3pb-1 and were collected with the STAR detector at the Relativistic Heavy Ion
Collider during the year 2005 with average beam polarizations of about 50%. The
ALL measurements cover jet transverse momenta 5 < pT < 30 GeV/c expanding the
pT coverage over previously published data. The results will be compared with
perturbative QCD evaluations and shown to provide sensitive constraints on the
gluon spin contribution to the nucleon spin.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 21:10:41 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Kowalik",
"Katarzyna",
"",
"for the STAR collaboration"
]
] |
0706.2668 | Yuri Kornyushin | Yuri Kornyushin | A jelly model for a ball of an extremely hot plasma | A simple model, which may be useful to understand the nature of a
ball lightning | null | null | null | physics.plasm-ph physics.ao-ph | null | A simple model is applied to study a high temperature rather dense plasma
ball. It is assumed that the ions and delocalized electrons are distributed
uniformly throughout the ball, and extra/missing charge is found in a thin
layer on the surface of a ball. It is shown in the framework of this model that
regarded plasma ball can be relatively stable as a metastable state.
Calculations show that electrostatic forces, repulsive forces between the ions,
and atmospheric pressure can provide stability of a plasma ball. Presented
model could be useful to understand the nature of a ball lightning.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 04:48:59 GMT"
},
{
"version": "v2",
"created": "Thu, 21 Jun 2007 03:39:17 GMT"
},
{
"version": "v3",
"created": "Wed, 4 Jul 2007 19:46:52 GMT"
}
] | 2007-07-04T00:00:00 | [
[
"Kornyushin",
"Yuri",
""
]
] |
0706.2669 | Edivaldo Moura Santos | E.M. Santos (for the Auger Collaboration) | A search for possible anisotropies of cosmic rays with 0.1<E<10 EeV in
the region of the Galactic Centre | Contribution to the 30th International Cosmic Ray Conference, Merida,
Mexico, July 2007, 4 pages, 6 figures | null | null | null | astro-ph | null | We present updated results for anisotropy searches in the direction of the
Galactic Center (GC) at energies in the ranges: 0.1<E<1 EeV and 1<E<10 EeV. We
use data from the Pierre Auger Observatory up to March, 2007. Present analyzes
are therefore based on a substantially larger data set than our previous
published results. A limit on the flux coming from a hypothetical point-like
neutron source at the GC for 1<E<10 EeV was imposed, and searches for extended
excesses were also performed.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 15:27:15 GMT"
},
{
"version": "v2",
"created": "Mon, 6 Aug 2007 22:39:44 GMT"
}
] | 2019-08-13T00:00:00 | [
[
"Santos",
"E. M.",
"",
"for the Auger Collaboration"
]
] |
0706.2670 | Alexei Borodin | Alexei Borodin and Christopher D. Sinclair | Correlation Functions of Asymmetric Real Matrices | 34 pages. This revision contains new content and some corrections | null | null | null | math-ph math.MP | null | We give a closed form for the correlation functions of ensembles of
asymmetric real matrices in terms of the Pfaffian of an antisymmetric matrix
formed from a $2 \times 2$ matrix kernel associated to the ensemble. We also
derive closed forms for the matrix kernel and correlation functions for
Ginibre's real ensemble.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 21:25:25 GMT"
},
{
"version": "v2",
"created": "Wed, 9 Apr 2008 04:19:00 GMT"
}
] | 2008-04-09T00:00:00 | [
[
"Borodin",
"Alexei",
""
],
[
"Sinclair",
"Christopher D.",
""
]
] |
0706.2671 | Aleksander Zujev | A. Zujev, R.T. Scalettar | Monte Carlo Simulations of an Extended Feynman-Kikuchi Model | 10 pages, 15 figures | null | 10.1103/PhysRevB.76.174524 | null | cond-mat.stat-mech | null | We present Quantum Monte Carlo simulations of a generalization of the
Feynman-Kikuchi model which includes the possibility of vacancies and
interactions between the particles undergoing exchange. By measuring the
winding number (superfluid density) and density structure factor, we determine
the phase diagram, and show that it exhibits regions which possess both
superfluid and charge ordering.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 21:28:29 GMT"
}
] | 2013-05-29T00:00:00 | [
[
"Zujev",
"A.",
""
],
[
"Scalettar",
"R. T.",
""
]
] |
0706.2672 | Robert Fletcher | R. S. Fletcher, X. L. Zhang, and S. L. Rolston | Using Three-Body Recombination to Extract Electron Temperatures of
Ultracold Plasmas | 5 pages, 3 figures | null | 10.1103/PhysRevLett.99.145001 | null | physics.atom-ph physics.plasm-ph | null | Three-body recombination, an important collisional process in plasmas,
increases dramatically at low electron temperatures, with an accepted scaling
of T_e^-9/2. We measure three-body recombination in an ultracold neutral xenon
plasma by detecting recombination-created Rydberg atoms using a
microwave-ionization technique. With the accepted theory (expected to be
applicable for weakly-coupled plasmas) and our measured rates we extract the
plasma temperatures, which are in reasonable agreement with previous
measurements early in the plasma lifetime. The resulting electron temperatures
indicate that the plasma continues to cool to temperatures below 1 K.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 22:10:19 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Fletcher",
"R. S.",
""
],
[
"Zhang",
"X. L.",
""
],
[
"Rolston",
"S. L.",
""
]
] |
0706.2673 | Lesfari Ahmed | A. Lesfari | Le th\'eor\`eme de Riemann-Roch et ses applications | 16 pages | null | null | null | math.CV math.AG | null | The Riemann-Roch theorem is of utmost importance in the algebraic geometric
theory of compact Riemann surfaces. It tells us how many linearly independent
meromorphic functions there are having certain restrictions on their poles. The
aim of this article is to present a simple direct proof of this theorem and
explore some of its numerous consequences. We also give an analytic proof of
the Riemann-Hurwitz formula. As an application, we compute the genus of some
interesting algebraic curves.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 21:32:45 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Lesfari",
"A.",
""
]
] |
0706.2674 | N. P. Ong | Y. Onose, N. P. Ong and C. Petrovic | The Lorenz number in CeCoIn$_5$ inferred from the thermal and charge
Hall currents | 6 pages, 7 figures Intro para slightly lengthened. Added 2 new ref | Europhys. Lett. 79, 17006 (2007) | 10.1209/0295-5075/80/37005 | null | cond-mat.str-el cond-mat.supr-con | null | The thermal Hall conductivity $\kappa_{xy}$ and Hall conductivity
$\sigma_{xy}$ in CeCoIn$_5$ are used to determine the Lorenz number ${\cal
L}_H$ at low temperature $T$. This enables the separation of the observed
thermal conductivity into its electronic and non-electronic parts. We uncover
evidence for a charge-neutral, field-dependent thermal conductivity, which we
identify with spin excitations. At low $T$, these excitations dominate the
scattering of charge carriers. We show that suppression of the spin excitations
in high fields leads to a steep enhancement of the electron mean-free-path,
which leads to an interesting scaling relation between the magnetoresistance,
thermal conductivity and $\sigma_{xy}$.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 21:35:58 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Jun 2007 17:29:41 GMT"
},
{
"version": "v3",
"created": "Thu, 28 Jun 2007 15:55:05 GMT"
},
{
"version": "v4",
"created": "Fri, 7 Sep 2007 17:26:45 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Onose",
"Y.",
""
],
[
"Ong",
"N. P.",
""
],
[
"Petrovic",
"C.",
""
]
] |
0706.2675 | Fabrizio Tamburini | F. Tamburini, G. Anzolin, G. Umbriaco, A. Bianchini, and C. Barbieri | Optical vortices with starlight: Implications for ground-based stellar
coronagraphy | 4 pages, 5 figures. Revised data analysis | null | 10.1051/0004-6361:200810469 | null | physics.optics astro-ph physics.ins-det | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using an l = 1 blazed fork-hologram at the focal plane of the Asiago 122 cm
telescope, we obtained optical vortices from the stellar system Rasalgethi
(alpha Herculis) and from the single star Arcturus (alpha Bootis). We have
analyzed the structure of the optical vortices obtained from non-monochromatic
starlight under very poor seeing conditions using a fast CCD camera to obtain
speckle patterns and carry out the lucky imaging technique, alternative to
adaptive optics. With the insertion of a red filter and of a Lyot stop we
performed l = 1 optical vortex coronography the double star HD74010. The
results are in agreement with theory and numerical simulations. Our results
open the way to applications of optical vortices to ground based astronomical
observations, in particular for coronagraphy with l > 1 masks. No intrinsic
orbital angular momentum was detected in the starlight.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 13:58:02 GMT"
},
{
"version": "v2",
"created": "Thu, 11 Oct 2007 15:32:22 GMT"
},
{
"version": "v3",
"created": "Fri, 27 Jun 2008 10:10:55 GMT"
}
] | 2010-07-21T00:00:00 | [
[
"Tamburini",
"F.",
""
],
[
"Anzolin",
"G.",
""
],
[
"Umbriaco",
"G.",
""
],
[
"Bianchini",
"A.",
""
],
[
"Barbieri",
"C.",
""
]
] |
0706.2676 | Masahide Yamaguchi | Kenji Kadota, Masahide Yamaguchi | D-term chaotic inflation in supergravity | 5 pages, to appear in Phys. Rev. D | Phys.Rev.D76:103522,2007 | 10.1103/PhysRevD.76.103522 | FTPI-MINN-07/21, UMN-TH-2610/07 | hep-ph astro-ph hep-th | null | Even though the chaotic inflation is one of the most popular inflation models
for its simple dynamics and compelling resolutions to the initial condition
problems, its realization in supergravity has been considered a challenging
task. We discuss how the chaotic inflation dominated by the D-term can be
induced in supergravity, which would give a new perspective on the inflation
model building in supergravity.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 13:08:18 GMT"
},
{
"version": "v2",
"created": "Sun, 11 Nov 2007 04:37:43 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kadota",
"Kenji",
""
],
[
"Yamaguchi",
"Masahide",
""
]
] |
0706.2677 | Yuri Shirman | Myron Bander, Jonathan L. Feng, Arvind Rajaraman, and Yuri Shirman | Unparticles: Scales and High Energy Probes | 16 pages, 2 tables, 6 figures; reference added, published version | Phys.Rev.D76:115002,2007 | 10.1103/PhysRevD.76.115002 | null | hep-ph hep-ex | null | Unparticles from hidden conformal sectors provide qualitatively new
possibilities for physics beyond the standard model. In the theoretical
framework of minimal models, we clarify the relation between energy scales
entering various phenomenological analyses. We show that these relations always
counteract the effective field theory intuition that higher dimension operators
are more highly suppressed, and that the requirement of a significant conformal
window places strong constraints on possible unparticle signals. With these
considerations in mind, we examine some of the most robust and sensitive probes
and explore novel effects of unparticles on gauge coupling evolution and
fermion production at high energy colliders. These constraints are presented
both as bounds on four-fermion interaction scales and as constraints on the
fundamental parameter space of minimal models.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 22:07:06 GMT"
},
{
"version": "v2",
"created": "Wed, 28 Nov 2007 22:01:35 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Bander",
"Myron",
""
],
[
"Feng",
"Jonathan L.",
""
],
[
"Rajaraman",
"Arvind",
""
],
[
"Shirman",
"Yuri",
""
]
] |
0706.2678 | Samoil Bilenky M. | S.M. Bilenky | CP-violation and unitarity triangle test of the Standard Model | On the basis of the lectures given to the students of SISSA (Trieste)
in 2006 | Phys.Part.Nucl.39:641-673,2008 | 10.1134/S1063779608050018 | null | hep-ph | null | Phenomenological issues of the CP violation in the quark sector of the
Standard Model are discussed. We consider quark mixing in the SM, standard and
Wolfenstein parametrization of the $CKM$ mixing matrix and unitarity triangle.
We discuss the phenomenology of the CP violation in $K^{0}_{L}$ and $B_{d}^{0}
(\bar B_{d}^{0})$-decays. The standard unitarity triangle fit of the existing
data is discussed. In appendix A we compare the $K^{0}\leftrightarrows \bar
K^{0}$, $B_{d,s}^{0}\leftrightarrows \bar B^{0}_{d,s}$ etc oscillations with
neutrino oscillations. In Appendix B we derive the evolution equation for
$M^{0}- \bar M^{0}$ system in the Weisskopf-Wigner approximation.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 22:28:52 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bilenky",
"S. M.",
""
]
] |
0706.2679 | Sasha Sodin | Omer Friedland and Sasha Sodin | Bounds on the concentration function in terms of Diophantine
approximation | null | C. R. Math. Acad. Sci. Paris 345 (2007), no. 9, 513--518 | null | null | math.PR | null | We demonstrate a simple analytic argument that may be used to bound the Levy
concentration function of a sum of independent random variables. The main
application is a version of a recent inequality due to Rudelson and Vershynin,
and its multidimensional generalisation.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 22:30:03 GMT"
},
{
"version": "v2",
"created": "Sat, 30 Jun 2007 18:24:55 GMT"
},
{
"version": "v3",
"created": "Mon, 13 Aug 2007 23:35:25 GMT"
},
{
"version": "v4",
"created": "Tue, 20 Nov 2007 23:25:54 GMT"
}
] | 2007-11-21T00:00:00 | [
[
"Friedland",
"Omer",
""
],
[
"Sodin",
"Sasha",
""
]
] |
0706.2680 | Robert Singleton Jr. Dr. | Robert L. Singleton Jr | BPS Explained I: Temperature Relaxation in a Plasma | 44 pages, 5 figures; added Los Alamos preprint number in text and
fixed typo in abstract | null | null | LA-UR-06-6738 | physics.plasm-ph hep-ph hep-th | null | This is the first of two lectures on a new powerful technique employed by
Brown, Preston, and Singleton (BPS) to calculate transport quantities in a
plasma. This exposition will be self-contained and intended for those who are
not specialists in quantum field theory, where the technique of dimensional
continuation exploited by BPS first arose. The method is highlighted by the
interesting analogy between the Coulomb logarithm of Lyman Spitzer on the one
hand, and the Lamb shift as calculated by Hans Bethe on the other. BPS employed
the method in a novel way that provides the leading and subleading behavior for
processes with competing disparate length or energy scales. They calculated the
temperature equilibration rate to leading and next-to-leading order in the
plasma number density for any two species in a plasma that are in thermal
equilibrium with themselves, but not necessarily with each other. A special
case of this calculation is the electron-ion temperature equilibration rate. It
should be emphasized that the BPS result is not a model, but rather it is an
exact calculation of the leading terms in a well-defined perturbation theory.
This exact result differs from approximations and models given in the
literature.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 22:30:31 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Jun 2007 19:50:20 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Singleton",
"Robert L.",
"Jr"
]
] |
0706.2681 | Cynthia J. Olson Reichhardt | A. Libal, C. Reichhardt, and C.J. Olson Reichhardt | Enhancing Mixing and Diffusion with Plastic Flow | 4 pages, 4 postscript figures | Phys. Rev. E 78, 031401 (2008) | 10.1103/PhysRevE.78.031401 | null | cond-mat.stat-mech cond-mat.soft | null | We use numerical simulations to examine two-dimensional particle mixtures
that strongly phase separate in equilibrium. When the system is externally
driven in the presence of quenched disorder, plastic flow occurs in the form of
meandering and strongly mixing channels. In some cases this can produce a fast
and complete mixing of previously segregated particle species, as well as an
enhancement of transverse diffusion even in the absence of thermal
fluctuations. We map the mixing phase diagram as a function of external driving
and quenched disorder parameters.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 22:34:19 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Libal",
"A.",
""
],
[
"Reichhardt",
"C.",
""
],
[
"Reichhardt",
"C. J. Olson",
""
]
] |
0706.2682 | Cyrille Marquet | Cyrille Marquet | A unified description of diffractive deep inelastic scattering with
saturation | 14 pages, 6 figures | Phys.Rev.D76:094017,2007 | 10.1103/PhysRevD.76.094017 | null | hep-ph | null | We propose a new description of inclusive diffraction in deep inelastic
scattering (DIS). The diffractive structure functions are expressed in the
dipole picture and contain heavy-quark contributions. The dipole scattering
amplitude, a saturation model fitted on inclusive DIS data, features a
saturation scale Q_s(x) larger than 1 GeV for x=10^{-5}. The q\bar{q}g
contribution to the diffractive final state is modeled in such a way that both
the large-Q^2 and small-beta limits are implemented. In the regime xpom<0.01 in
which saturation is expected to be relevant, we obtain a parameter-free
description of the HERA data with chi^2/points=1.2.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 22:47:27 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Marquet",
"Cyrille",
""
]
] |
0706.2683 | Joanna Thomas-Osip | Joanna Thomas-Osip, Andrew McWilliam, M. M. Phillips, N. Morrell, I.
Thompson, T. Folkers, and M. Lopez-Morales | Calibration of the Relationship between Precipitable Water Vapor and 225
GHz Atmospheric Opacity via Optical Echelle Spectroscopy at Las Campanas
Observatory | 14 pages, 5 tables, 9 figures, accepted by PASP in May 2007 | null | 10.1086/520097 | null | astro-ph | null | We report precipitable water vapor (PWV) measurements made at Las Campanas
Observatory using optical spectra of H2O lines obtained with the Magellan
echelle spectrograph, and calculated using a robust technique that is accurate
to 5-10%. Calibration of the relationship between our PWV measurements and
opacity values at 225 GHz was made possible by simultaneous tipping radiometer
observations. Based on this calibration, we present Las Campanas Observatory
winter-time precipitable water vapor statistics, measured using the tipping
radiometer, during a two month campaign. The median value of 2.8 +- 0.3 mm is
consistent with that measured at the nearby La Silla Observatory during the VLT
site survey. We conclude that, in the Southern hemisphere winter months, we can
expect good conditions for infrared observing (<~1.5 mm) approximately 10% of
the time at Las Campanas Observatory.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 22:44:04 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Thomas-Osip",
"Joanna",
""
],
[
"McWilliam",
"Andrew",
""
],
[
"Phillips",
"M. M.",
""
],
[
"Morrell",
"N.",
""
],
[
"Thompson",
"I.",
""
],
[
"Folkers",
"T.",
""
],
[
"Lopez-Morales",
"M.",
""
]
] |
0706.2684 | Anatoli Polkovnikov | Yariv Kafri, David R. Nelson, Anatoli Polkovnikov | Unzipping Vortices in Type-II Superconductors | 19 pages 15 figures | Phys. Rev. B 76, 144501 (2007) | 10.1103/PhysRevB.76.144501 | null | cond-mat.stat-mech cond-mat.soft cond-mat.supr-con | null | The unzipping of vortex lines using magnetic-force microscopy from extended
defects is studied theoretically. We study both the unzipping isolated vortex
from common defects, such as columnar pins and twin-planes, and the unzipping
of a vortex from a plane in the presence of other vortices. We show, using
analytic and numerical methods, that the universal properties of the unzipping
transition of a single vortex depend only on the dimensionality of the defect
in the presence and absence of disorder. For the unzipping of a vortex from a
plane populated with many vortices is shown to be very sensitive to the
properties of the vortices in the two-dimensional plane. In particular such
unzipping experiments can be used to measure the ``Luttinger liquid parameter''
of the vortices in the plane. In addition we suggest a method for measuring the
line tension of the vortex directly using the experiments.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 22:44:34 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Kafri",
"Yariv",
""
],
[
"Nelson",
"David R.",
""
],
[
"Polkovnikov",
"Anatoli",
""
]
] |
0706.2685 | Celso C. Nishi | Celso C. Nishi | Structure of potentials with $N$ Higgs doublets | 11 pages. Revtex4. Typos corrected. Few comments added | Phys.Rev.D76:055013,2007 | 10.1103/PhysRevD.76.055013 | null | hep-ph hep-th math-ph math.MP | null | Extensions of the Standard Model with $N$ Higgs doublets are simple
extensions presenting a rich mathematical structure. An underlying Minkowski
structure emerges from the study of both variable space and parameter space.
The former can be completely parametrized in terms of two future lightlike
Minkowski vectors with spatial parts forming an angle whose cosine is
$-(N-1)^{-1}$. For the parameter space, the Minkowski parametrization enables
one to impose sufficient conditions for bounded below potentials, characterize
certain classes of local minima and distinguish charge breaking vacua from
neutral vacua. A particular class of neutral minima presents a degenerate mass
spectrum for the physical charged Higgs bosons.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 19:03:51 GMT"
},
{
"version": "v2",
"created": "Mon, 1 Oct 2007 12:30:21 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Nishi",
"Celso C.",
""
]
] |
0706.2686 | Venkatramani Lakshmibai | V. Lakshmibai and H. Mukherjee | Singular Loci of Hibi toric varieties | 25 pages | Journal of Ramanujan Mathematical Soc. 26, No 1 (2011) 1-29 | null | null | math.AG | null | We first construct explicit bases for the cotangent spaces at singular points
on Hibi toric varieties, i.e., toric varieties associated to distributive
lattices. We then determine the singular loci of these toric varieties.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 22:55:54 GMT"
}
] | 2014-05-06T00:00:00 | [
[
"Lakshmibai",
"V.",
""
],
[
"Mukherjee",
"H.",
""
]
] |
0706.2687 | Sergey Koposov E. | S. Koposov (1,2), V. Belokurov (2), N.W. Evans (2), P.C. Hewett (2),
M.J. Irwin (2), G. Gilmore (2), D.B. Zucker (2), H.-W. Rix (1), M. Fellhauer
(2), E. F. Bell (1), E. V. Glushkova (3) ((1) Max Planck Institute for
Astronomy, Heidelberg, Germany, (2) Institute of Astronomy, Cambridge, UK,
(3) Sternberg Astronomical Institute, Moscow, Russia) | The Luminosity Function of the Milky Way Satellites | accepted to ApJ | Astrophys.J.686:279-291,2008 | 10.1086/589911 | null | astro-ph | null | We quantify the detectability of stellar Milky Way satellites in the Sloan
Digital Sky Survey (SDSS) Data Release 5. We show that the effective search
volumes for the recently discovered SDSS--satellites depend strongly on their
luminosity, with their maximum distance, $D_{max}$, substantially smaller than
the Milky Way halo's virial radius. Calculating the maximum accessible volume,
$V_{max}$, for all faint detected satellites, allows the calculation of the
luminosity function for Milky Way satellite galaxies, accounting quantitatively
for their detectability. We find that the number density of satellite galaxies
continues to rise towards low luminosities, but may flatten at $M_V \sim -5$;
within the uncertainties, the luminosity function can be described by a single
power law $dN/dM_{V}= 10 \times 10^{0.1 (M_V+5)}$, spanning luminosities from
$M_V=-2$ all the way to the luminosity of the Large Magellanic Cloud. Comparing
these results to several semi-analytic galaxy formation models, we find that
their predictions differ significantly from the data: either the shape of the
luminosity function, or the surface brightness distributions of the models, do
not match.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 16:24:03 GMT"
},
{
"version": "v2",
"created": "Mon, 19 May 2008 13:03:58 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Koposov",
"S.",
""
],
[
"Belokurov",
"V.",
""
],
[
"Evans",
"N. W.",
""
],
[
"Hewett",
"P. C.",
""
],
[
"Irwin",
"M. J.",
""
],
[
"Gilmore",
"G.",
""
],
[
"Zucker",
"D. B.",
""
],
[
"Rix",
"H. -W.",
""
],
[
"Fellhauer",
"M.",
""
],
[
"Bell",
"E. F.",
""
],
[
"Glushkova",
"E. V.",
""
]
] |
0706.2688 | Marco Finazzi | R. Bertacco, S. Brivio, M. Cantoni, A. Cattoni, D. Petti, M. Finazzi,
F. Ciccacci, A. A. Sidorenko, M. Ghidini, G. Allodi, and R. De Renzi | Proximity effects induced by a gold layer on La0.67Sr0.33MnO3 thin films | null | null | 10.1063/1.2778353 | null | cond-mat.mtrl-sci | null | We report about La0.67Sr0.33MnO3 single crystal manganite thin films in
interaction with a gold capping layer. With respect to uncoated manganite
layers of the same thickness, Au-capped 4 nm-thick manganite films reveal a
dramatic reduction (about 185 K) of the Curie temperature TC and a lower
saturation low-temperature magnetization M0. A sizeable TC reduction (about 60
K) is observed even when an inert SrTiO3 layer is inserted between the gold
film and the 4 nm-thick manganite layer, suggesting that this effect might have
an electrostatic origin.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 13:52:35 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bertacco",
"R.",
""
],
[
"Brivio",
"S.",
""
],
[
"Cantoni",
"M.",
""
],
[
"Cattoni",
"A.",
""
],
[
"Petti",
"D.",
""
],
[
"Finazzi",
"M.",
""
],
[
"Ciccacci",
"F.",
""
],
[
"Sidorenko",
"A. A.",
""
],
[
"Ghidini",
"M.",
""
],
[
"Allodi",
"G.",
""
],
[
"De Renzi",
"R.",
""
]
] |
0706.2689 | Andrei Derevianko | James S. Cohen and Andrei Derevianko | Long-range forces between two excited mercury atoms and associative
ionization | accepted in Phys Rev A | null | 10.1103/PhysRevA.76.012706 | null | physics.atom-ph | null | The long-range quadrupole-quadrupole ($\sim R^{-5}$) and leading dispersion
($\sim R^{-6}$) interactions between all pairs of excited Hg($6s6p$) $^3P_0$,
$^3P_1$, $^3P_2$, and $^1P_1$ atoms are determined. The quadrupole moments are
calculated using the {\it ab initio} relativistic configuration-interaction
method coupled with many-body perturbation theory. The van der Waals
coefficients are approximated using previously calculated static
polarizabilities and expressions for the dispersion energy that are validated
with similar systems. The long-range interactions are critical for associative
ionization in thermal and cold collisions, and are found to be quite different
for different pairs of interacting states. Based on this knowledge and the
short-range parts of previously calculated potential curves, improved estimates
of the chemi-ionization cross sections are obtained.
| [
{
"version": "v1",
"created": "Mon, 18 Jun 2007 23:51:24 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Cohen",
"James S.",
""
],
[
"Derevianko",
"Andrei",
""
]
] |
0706.2690 | Alfio Bonanno | Alfio Bonanno, Vadim Urpin | Hydromagnetic Instability in plane Couette Flow | 6 pages, 5 figures. To appear on PRE | Phys.Rev.E76:016303,2007 | 10.1103/PhysRevE.76.016303 | null | astro-ph | null | We study the stability of a compressible magnetic plane Couette flow and show
that compressibility profoundly alters the stability properties if the magnetic
field has a component perpendicular to the direction of flow. The necessary
condition of a newly found instability can be satisfied in a wide variety of
flows in laboratory and astrophysical conditions. The instability can operate
even in a very strong magnetic field which entirely suppresses other MHD
instabilities. The growth time of this instability can be rather short and
reach $\sim 10$ shear timescales.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 00:25:34 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bonanno",
"Alfio",
""
],
[
"Urpin",
"Vadim",
""
]
] |
0706.2691 | Roland Mathieu | R. Mathieu, J. P. He, Y. Kaneko, H. Yoshino, A. Asamitsu, Y. Tokura, | Logarithmic growth law in the two-dimensional Ising spin glass state
resulting from the electron doping in single-layered manganites | REVTeX 4 style; 5 pages, 4 figures | Phys. Rev. B 76, 014436 (2007). | 10.1103/PhysRevB.76.014436 | null | cond-mat.mtrl-sci cond-mat.str-el | null | The ac-susceptibility of the electron doped single-layered manganite
La$_{1.1}$Sr$_{0.9}$MnO$_4$ is analyzed in detail. A quasi two-dimensional
(2$D$) antiferromagnetic (AFM) order with Ising anisotropy is stabilized below
$T_N$ $\sim$ 80K. We show that below $T_N$, a rare 2$D$ spin-glass (SG)
correlation develops with the same Ising anisotropy as the AFM state. Using
simple scaling arguments of the droplet model, we derive a scaling form for the
ac-susceptibility data of a 2$D$ SG, which our experimental data follows fairly
well. Due to simplifications in this 2$D$ case, the proposed scaling form only
contains two unknown variables $\psi\nu$ and $\tau_0$. Hence, the logarithmic
growth law of the SG correlation predicted by the droplet model is convincingly
evidenced by the scaling of our experimental data. The origin and nature of
this 2$D$ SG state is also discussed.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 00:23:54 GMT"
}
] | 2007-07-31T00:00:00 | [
[
"Mathieu",
"R.",
""
],
[
"He",
"J. P.",
""
],
[
"Kaneko",
"Y.",
""
],
[
"Yoshino",
"H.",
""
],
[
"Asamitsu",
"A.",
""
],
[
"Tokura",
"Y.",
""
]
] |
0706.2692 | Stephen Curran Dr | S. J. Curran, P. Tzanavaris, M. T. Murphy, J. K. Webb and Y. M.
Pihlstroem | Detection of broad 21-cm absorption at z = 0.656 in the complex
sight-line towards 3C336 | 5 pages, 3 figures, accepted by MNRAS Letters | null | 10.1111/j.1745-3933.2007.00354.x | null | astro-ph | null | We report the detection of 21-cm absorption at z = 0.656 towards 1622+238
(3C336). The line is very broad with a Full-Width Half Maximum (FWHM) of 235
km/s, giving a velocity integrated optical depth of 2.2 km/s. The centroid of
the line is offset from that of the known damped Lyman-alpha absorption (DLA)
system by 50 km/s, and if the Lyman-alpha and 21-cm absorption are due to the
same gas, we derive a spin temperature of < 60 K, which would be the lowest yet
in a DLA. The wide profile, which is over four times wider than that of any
other DLA, supports the hypothesis that the hydrogen absorption is occurring
either in the disk of a large underluminous spiral or a group of dim
unidentified galaxies, associated with the single object which has been
optically identified at this redshift.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 00:26:29 GMT"
},
{
"version": "v2",
"created": "Fri, 27 Jul 2007 04:26:48 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Curran",
"S. J.",
""
],
[
"Tzanavaris",
"P.",
""
],
[
"Murphy",
"M. T.",
""
],
[
"Webb",
"J. K.",
""
],
[
"Pihlstroem",
"Y. M.",
""
]
] |
0706.2693 | Hugo F. Arellano | H. F. Arellano and M. Girod | Reaction cross sections for proton scattering from stable and unstable
nuclei based on a microscopic approach | 11 pages, 4 figures, submitted to Phys. Rev. C | Phys.Rev.C76:034602,2007 | 10.1103/PhysRevC.76.034602 | null | nucl-th | null | Microscopic optical model potential results for reaction cross sections of
proton elastic scattering are presented. The applications cover the 10-1000 MeV
energy range and consider both stable and unstable nuclei. The study is based
on in-medium g-matrix full-folding optical model approach with the appropriate
relativistic kinematic corrections needed for the higher energy applications.
The effective interactions are based on realistic NN potentials supplemented
with a separable non-Hermitian term to allow optimum agreement with current NN
phase-shift analyzes, particularly the inelasticities above pion production
threshold. The target ground-state densities are obtained from
Hartree-Fock-Bogoliubov calculations based on the finite range, density
dependent Gogny force. The evaluated reaction cross sections for proton
scattering are compared with measurements and their systematics is analyzed. A
simple function of the total cross sections in terms of the atomic mass number
is observed at high energies. At low energies, however, discrepancies with the
available data are observed, being more pronounced in the lighter systems.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 00:27:18 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Arellano",
"H. F.",
""
],
[
"Girod",
"M.",
""
]
] |
0706.2694 | Robert Foot | R. Foot | Mirror dark matter | about 7 pages | Int.J.Mod.Phys.A22:4951-4957,2007 | 10.1142/S0217751X0703830X | null | hep-ph astro-ph | null | A mirror sector of particles and forces provides a simple explanation of the
inferred dark matter of the Universe. The status of this theory is reviewed -
with emphasis on how the theory explains the impressive DAMA/NaI annual
modulation signal, whilst also being consistent with the null results of the
other direct detection experiments.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 00:35:29 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Foot",
"R.",
""
]
] |
0706.2695 | Hugo F. Arellano | H. F. Arellano and Eric Bauge | Functional medium-dependence of the nonrelativistic optical model
potential | 11 pages, 5 figures, submitted to Phys. Rev. C | Phys.Rev.C76:014613,2007 | 10.1103/PhysRevC.76.014613 | null | nucl-th | null | By examining the structure in momentum and coordinate space of a two-body
interaction spherically symmetric in its local coordinate, we demonstrate that
it can be disentangled into two distinctive contributions. One of them is a
medium-independent and momentum-conserving term, whereas the other is
functionally --and exclusively-- proportional to the radial derivative of the
reduced matrix element. As example, this exact result was applied to the
unabridged optical potential in momentum space, leading to an explicit
separation between the medium-free and medium-dependent contributions. The
latter does not depend on the strength of the reduced effective interaction but
only on its variations with respect to the density. The modulation of radial
derivatives of the density enhances the effect in the surface and suppresses it
in the saturated volume. The generality of this result may prove to be useful
for the study of surface-sensitive phenomena.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 00:39:40 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Arellano",
"H. F.",
""
],
[
"Bauge",
"Eric",
""
]
] |
0706.2696 | Takahiro Kudoh | Takahiro Kudoh (1), Shantanu Basu (2), Youichi Ogata (3), Takashi Yabe
(4) ((1) National Astronomical Observatory of Japan, (2) University of
Western Ontario, (3) Tokyo Institute of Technology, (4) Tokyo Institute of
Technology) | Three-dimensional simulations of molecular cloud fragmentation regulated
by magnetic fields and ambipolar diffusion | 8 pages, 11 figures, accepted for publication in MNRAS, a preprint
with fine figures at http://yso.mtk.nao.ac.jp/~kudoh/publist_e.html | Mon.Not.Roy.Astron.Soc.380:499-505,2007 | 10.1111/j.1365-2966.2007.12119.x | null | astro-ph | null | We employ the first fully three-dimensional simulation to study the role of
magnetic fields and ion-neutral friction in regulating gravitationally-driven
fragmentation of molecular clouds. The cores in an initially subcritical cloud
develop gradually over an ambipolar diffusion time while the cores in an
initially supercritical cloud develop in a dynamical time. The infall speeds on
to cores are subsonic in the case of an initially subcritical cloud, while an
extended (\ga 0.1 pc) region of supersonic infall exists in the case of an
initially supercritical cloud. These results are consistent with previous
two-dimensional simulations. We also found that a snapshot of the relation
between density (rho) and the strength of the magnetic field (B) at different
spatial points of the cloud coincides with the evolutionary track of an
individual core. When the density becomes large, both relations tend to B
\propto \rho^{0.5}.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 00:48:44 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kudoh",
"Takahiro",
""
],
[
"Basu",
"Shantanu",
""
],
[
"Ogata",
"Youichi",
""
],
[
"Yabe",
"Takashi",
""
]
] |
0706.2697 | Yukio Nemoto | Yukio Nemoto, Masakiyo Kitazawa, Teiji Kunihiro | Fluctuations of the chiral condensate and quasi-particle spectra near
phase transition | 10 pages, 5 figures, talk given at Mini-Workshop on ``Strongly
Coupled Quark-Gluon Plasma: SPS, RHIC and LHC", Nagoya, Japan, 16-18 Feb.
2007 | null | null | null | hep-ph nucl-th | null | We investigate the quark spectrum near but above the critical temperature of
the chiral transition, taking into account the precursory soft modes. It is
found that there appear novel excitation spectra of quasi-quarks and
quasi-antiquarks with a three-peak structure. By a detailed analysis on the
formation of the three-peak structure using Yukawa models, it is shown that the
new quark spectra originate from the mixing between a quark (anti-quark) and an
antiquark hole (quark hole) caused by a resonant scattering of the quasi-quark
with the soft modes which have a small but finite excitation energy with a
small width near the critical temperature.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 01:07:35 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Nemoto",
"Yukio",
""
],
[
"Kitazawa",
"Masakiyo",
""
],
[
"Kunihiro",
"Teiji",
""
]
] |
0706.2698 | Nadezhda Tsoneva Larionova | N. Tsoneva and H. Lenske | Pygmy dipole resonance in exotic nuclei | International Workshop on Nuclear Physics 28th Course - Radioactive
Beams, Nuclear Dynamics and Astrophysics, Ettore Majorana Center for
Scientific Culture | Prog.Part.Nucl.Phys.59:317-319,2007 | 10.1016/j.ppnp.2006.12.030 | null | nucl-th | null | The evolution of the PDR strength with the neutron excess is investigated in
Sn isotopic and N=82 isotonic chains with regard to its possible connection
with the neutron skin thickness. For this purpose a recently proposed method
incorporating both HFB and multi-phonon QPM theory is applied. Analysis of the
corresponding neutron and proton dipole transition densities is presented.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 13:49:47 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Tsoneva",
"N.",
""
],
[
"Lenske",
"H.",
""
]
] |
0706.2699 | Eyo Ita III | Eyo Eyo Ita III | Instanton representation of Plebanski gravity. Application to Bianchi
Type A metrics | 12 pages. Background material for revised journal article | null | null | null | gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the instanton representation method we construct a general solution for
GR in the spatially homogeneous case restricted to diagonal variables. This
paper provides a testing ground and physical intuition for many of the salient
features of general relativity which it is suggested should be preserved in the
full theory.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 01:59:05 GMT"
},
{
"version": "v2",
"created": "Tue, 3 Jul 2007 04:53:57 GMT"
},
{
"version": "v3",
"created": "Mon, 26 May 2008 19:31:49 GMT"
},
{
"version": "v4",
"created": "Tue, 24 Jun 2008 19:26:47 GMT"
},
{
"version": "v5",
"created": "Wed, 21 Apr 2010 19:42:58 GMT"
},
{
"version": "v6",
"created": "Fri, 18 Mar 2011 07:38:08 GMT"
}
] | 2011-03-21T00:00:00 | [
[
"Ita",
"Eyo Eyo",
"III"
]
] |
0706.2700 | Takehiko Yasuda | Takehiko Yasuda | Universal flattening of Frobenius | 25 pages; v4. a full revision, notations changed, the isomorphism of
the F-blowup and the G-Hilbert scheme has been generalized to the non-abelian
case, errors corrected, the introduction shortened. v5. minor revision, to
appear in the American Journal of Mathematics | null | null | null | math.AG math.AC | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For a variety $X$ of positive characteristic and a non-negative integer $e$,
we define its $e$-th F-blowup to be the universal flattening of the
$e$-iterated Frobenius of $X$. Thus we have the sequence (a set labeled by
non-negative integers) of blowups of $X$. Under some condition, the sequence
stabilizes and leads to a nice (for instance, minimal or crepant) resolution.
For tame quotient singularities, the sequence leads to the $G$-Hilbert scheme.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 02:10:08 GMT"
},
{
"version": "v2",
"created": "Sat, 7 Jul 2007 03:56:34 GMT"
},
{
"version": "v3",
"created": "Fri, 27 Jul 2007 23:19:26 GMT"
},
{
"version": "v4",
"created": "Wed, 22 Jul 2009 08:25:38 GMT"
},
{
"version": "v5",
"created": "Mon, 24 Oct 2011 01:36:55 GMT"
}
] | 2011-10-25T00:00:00 | [
[
"Yasuda",
"Takehiko",
""
]
] |
0706.2701 | L. C. Garcia de Andrade | Garcia de Andrade | Differential rotation of stretched and twisted thick magnetic flux tube
dynamos in Riemannian spaces | null | null | null | null | astro-ph | null | The topological mapping between a torus of big radius and a sphere is applied
to the Riemannian geometry of a stretched and twisted very thick magnetic flux
tube, to obtain spherical dynamos solving the magnetohydrodynamics (MHD)
self-induction equation for the magnetic flux tubes undergoing differential
(non-uniform) rotation along the tube magnetic axis. Constraints on the shear
is also computed. It is shown that when the hypothesis of the convective
cyclonic dynamo is used the rotation is constant and a solid rotational body is
obtained. As usual toroidal fields are obtained from poloidal magnetic field
and these fields may be expressed in terms of the differential rotation
${\Omega}(r,{\theta}(s))$. In the case of non-cyclonic dynamos the torsion in
the Frenet frame is compute in terms of the dynamo constant. The flux tube
shear $\frac{\partial}{{\partial}r}{\Omega}$ is also computed. The untwisted
tube case is shown to be trivial in the sense that does not support any dynamo
action. This case is in agreement with Cowling antidynamo theorem, since in the
untwisted case the tube becomes axially symmetric which the refereed theorem
rules out. We also show that it is consistent with the Zeldovich antidynamo
theorem which rules out planar dynamos. Knowledge of the differential rotation
of the Earth, for example, allows one to place limits on the curvature and
torsion of the flux tube axis and vice-versa, knowledge of the topology permit
us to infer differential rotation and other physical parameters of the stars
and planets.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 02:10:33 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"de Andrade",
"Garcia",
""
]
] |
0706.2702 | Eyo Ita III | Eyo Eyo Ita III | Nonlinear gravitons from the initial value constraints of GR in Ashtekar
variables | 4 pages | Proceedings from the Spanish Relativity Meeting (ERE 2010) | null | DAMTP 2007-60 | gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we provide a possible realization of Penrose's idea of
nonlinear gravitons by constructing a solution to the initial value constraints
in Ashtekar variables. The solution inputs are a spatial SU(2) connection and
two free functions of position, and can be constructed as a formal operatorial
expansion in powers of the cosmological constant about spacetimes of Petrov
Type O. We first present the linear case, and then provide a simple nonlinear
example to first order using a spatially homogeneous connection.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 02:19:00 GMT"
},
{
"version": "v2",
"created": "Tue, 3 Jul 2007 04:59:09 GMT"
},
{
"version": "v3",
"created": "Mon, 26 May 2008 23:03:26 GMT"
},
{
"version": "v4",
"created": "Wed, 21 Apr 2010 19:48:24 GMT"
},
{
"version": "v5",
"created": "Fri, 17 Feb 2012 11:52:47 GMT"
}
] | 2012-02-20T00:00:00 | [
[
"Ita",
"Eyo Eyo",
"III"
]
] |
0706.2703 | Usama Khawaja Al | U. Al Khawaja | Exact Solitonic Solutions of the Gross-Pitaevskii Equation with a Linear
Potential | null | null | null | null | cond-mat.other | null | We derive classes of exact solitonic solutions of the time-dependent
Gross-Pitaevskii equation with repulsive and attractive interatomic
interactions. The solutions correspond to a string of bright solitons with
phase difference between adjacent solitons equal to $\pi$. While the relative
phase, width, and distance between adjacent solitons turn out to be a constant
of the motion, the center of mass of the string moves with a constant
acceleration arising from the inhomogeneity of the background.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 02:50:23 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Khawaja",
"U. Al",
""
]
] |
0706.2704 | Yanxia Zhang | D. Wang, Y. X. Zhang, C. Liu, Y. H.Zhao | Kernel Regression For Determining Photometric Redshifts From Sloan
Broadband Photometry | 6 pages,2 figures, accepted for publication in MNRAS | null | 10.1111/j.1365-2966.2007.12129.x | null | astro-ph | null | We present a new approach, kernel regression, to determine photometric
redshifts for 399,929 galaxies in the Fifth Data Release of the Sloan Digital
Sky Survey (SDSS). In our case, kernel regression is a weighted average of
spectral redshifts of the neighbors for a query point, where higher weights are
associated with points that are closer to the query point. One important design
decision when using kernel regression is the choice of the bandwidth. We apply
10-fold cross-validation to choose the optimal bandwidth, which is obtained as
the cross-validation error approaches the minimum. The experiments show that
the optimal bandwidth is different for diverse input patterns, the least rms
error of photometric redshift estimation arrives at 0.019 using color+eClass as
the inputs, the less rms error amounts to 0.020 using ugriz+eClass as the
inputs. Here eClass is a galaxy spectra type. Then the little rms scatter is
0.021 with color+r as the inputs.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 02:51:51 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Jun 2007 01:51:45 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Wang",
"D.",
""
],
[
"Zhang",
"Y. X.",
""
],
[
"Liu",
"C.",
""
],
[
"Zhao",
"Y. H.",
""
]
] |
0706.2705 | Usama Khawaja Al | U. Al Khawaja | Exact Solitonic Solutions of the One-Dimensional Gross-Pitaevskii
Equation with a Time-Dependent Harmonic Potential and Interatomic Interaction | null | null | null | null | cond-mat.other | null | We derive exact solitonic solutions of the one-dimensional time-dependent
Gross-Pitaevskii equation with time-dependent strengths of the harmonic
external potential and the interatomic interaction. The time-dependence of the
external potential and interatomic interaction are given in terms of a general
function of time. For an oscillating strength of the external potential, the
solutions correspond to breathing single and multiple solitons. The amplitude
and frequency of the oscillating potential can be used to control the dynamics
of the center of mass of the solitons. For certain values of these parameters,
the solitons can be {\it trapped} at the center of the harmonic potential.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 03:08:32 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Khawaja",
"U. Al",
""
]
] |
0706.2706 | Katsuyoshi Ohara | Katsuyoshi Ohara and Nobuki Takayama | Holonomic rank of A-hypergeometric differential-difference equations | 16 pages | null | null | null | math.CA | null | We introduce A-hypergeometric differential-difference equation and prove that
its holonomic rank is equal to the normalized volume of A with giving a set of
convergent series solutions.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 03:29:24 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Ohara",
"Katsuyoshi",
""
],
[
"Takayama",
"Nobuki",
""
]
] |
0706.2707 | Stephanie van Willigenburg | M. D. Atkinson and S. J. van Willigenburg | The p-modular Descent Algebra of the Symmetric Group | 8 pages | Bull. of the London Math. Soc. 29:407-414 (1997) | null | null | math.CO | null | The descent algebra of the symmetric group, over a field of non-zero
characteristic p, is studied. A homomorphism into the algebra of generalised
p-modular characters of the symmetric group is defined. This is then used to
determine the radical, and its nilpotency index. It also allows the irreducible
representations of the descent algebra to be described.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 03:44:28 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Atkinson",
"M. D.",
""
],
[
"van Willigenburg",
"S. J.",
""
]
] |
0706.2708 | Tapan K. Nayak | Tapan K. Nayak | Overview of event-by-event analysis of high energy nuclear collisions | Invited talk at the "XIth International Workshop on Correlation and
Fluctuation in Multiparticle Production", Nov 21-24, 2006, Hangzhou, China
(19 pages) | Int.J.Mod.Phys.E16:3303-3322,2008 | 10.1142/S0218301307009282 | null | nucl-ex | null | The event-by-event analysis of high energy nuclear collisions aims at
revealing the richness of the underlying event structures and provide unique
measures of dynamical fluctuations associated with QGP phase transition. The
major challenge in these studies is to separate the dynamical fluctuations from
the many other sources which contribute to the measured values. We present the
fluctuations in terms of event multiplicity, mean transverse momentum, elliptic
flow, source sizes, particle ratios and net charge distributions. In addition,
we discuss the effect of long range correlations, disoriented chiral
condensates and presence of jets. A brief review of various probes used for
fluctuation studies and available experimental results are presented.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 03:46:05 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Nayak",
"Tapan K.",
""
]
] |
0706.2709 | Frank Close Prof | F E Close | Rumsfeld Hadrons | Talk at Flavor Physics Conference, Slovenia and PIC Annecy | ECONFC070512:020,2007 | 10.1080/00107510802607804 | null | hep-ph | null | Donald Rumsfeld, in attempting to excuse the inexcusable, once (in)famously
said that ``there are things that we know we know; there are things that we
know we don't know; and then there are things that we don't know that we don't
know". Recent discoveries about hadrons with heavy flavours fall into those
categories. It is of course the third category that is the most tantalising,
but lessons from the first two may help resolve the third.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 14:01:20 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Close",
"F E",
""
]
] |
0706.2710 | John C. Lattanzio | Peter P. Eggleton, David S. P. Dearborn, John C. Lattanzio | Compulsory Deep Mixing of 3He and CNO Isotopes in the Envelopes of
low-mass Red Giants | Final accepted version (submitted to Astrophys J in Jan 2007...) | AIPConf.Proc.948:27-34,2007 | 10.1063/1.2818983 | null | astro-ph | null | Three-dimensional stellar modeling has enabled us to identify a deep-mixing
mechanism that must operate in all low mass giants. This mixing process is not
optional, and is driven by a molecular weight inversion created by the
3He(3He,2p)4He reaction. In this paper we characterize the behavior of this
mixing, and study its impact on the envelope abundances. It not only eliminates
the problem of 3He overproduction, reconciling stellar and big bang
nucleosynthesis with observations, but solves the discrepancy between observed
and calculated CNO isotope ratios in low mass giants, a problem of more than 3
decades' standing. This mixing mechanism, which we call `$\delta\mu$-mixing',
operates rapidly (relative to the nuclear timescale of overall evolution, ~
10^8 yrs) once the hydrogen burning shell approaches the material homogenized
by the surface convection zone. In agreement with observations, Pop I stars
between 0.8 and 2.0$\Msun$ develop 12C/13C ratios of 14.5 +/- 1.5, while Pop II
stars process the carbon to ratios of 4.0 +/- 0.5. In stars less than
1.25$\Msun$, this mechanism also destroys 90% to 95% of the 3He produced on the
main sequence.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 05:25:57 GMT"
},
{
"version": "v2",
"created": "Thu, 29 Nov 2007 23:30:24 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Eggleton",
"Peter P.",
""
],
[
"Dearborn",
"David S. P.",
""
],
[
"Lattanzio",
"John C.",
""
]
] |
0706.2711 | Stephanie van Willigenburg | N. Bergeron and S.J. van Willigenburg | On the Descent Algebra of Type $D$ | 7 pages | J. of Algebra 206:699-705 (1998) | 10.1006/jabr.1998.7428 | null | math.CO | null | Here we give a combinatorial interpretation of Solomon's rule for
multiplication in the descent algebra of Weyl groups of type $D$, $\Sigma D_n$.
From here we show that $\Sigma D_n$ is a homomorphic image of the descent
algebra of the hyperoctahedral group, $\Sigma B_{n-2}$.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 04:55:40 GMT"
}
] | 2016-11-08T00:00:00 | [
[
"Bergeron",
"N.",
""
],
[
"van Willigenburg",
"S. J.",
""
]
] |
0706.2712 | H.-N. Li | Haining Li (1,2), Hong Wu (1,3), Chen Cao (1,2), Yinan Zhu (1,2)
((1)NAOC, China; (2)GUCAS, China; (3)Visiting Scholar, IfA, University of
Hawaii) | Morphological Dependence of MIR Properties of SDSS Galaxies in the
Spitzer SWIRE Survey | Accepted for publication by AJ. 18 pages, 14 figures, and 4 tables | null | 10.1086/520807 | null | astro-ph | null | We explore the correlation between morphological types and mid-infrared (MIR)
properties of an optically flux-limited sample of 154 galaxies from the Forth
Data Release (DR4) of Sloan Digital Sky Survey (SDSS), cross-correlated with
Spitzer SWIRE (Spitzer Wide-Area InfraRed Extragalactic Survey) fields of
ELAIS-N1, ELAIS-N2 and Lockman Hole. Aperture photometry is performed on the
SDSS and Spitzer images to obtain optical and MIR properties. The morphological
classifications are given based on both visual inspection and bulge-disk
decomposition on SDSS g- and r-band images. The average bulge-to-total ratio
(B/T) is a smooth function over different morphological types. Both the
8um(dust) and 24um(dust) luminosities and their relative luminosity ratios to
3.6um (MIR dust-to-star ratios) present obvious correlations with both the
Hubble T-type and B/T. The early-type galaxies notably differ from the
late-types in the MIR properties, especially in the MIR dust-to-star ratios. It
is suggested that the MIR dust-to-star ratio is an effective way to separate
the early-type galaxies from the late-type ones. Based on the tight correlation
between the stellar mass and the 3.6um luminosity, we have derived a formula to
calculate the stellar mass from the latter. We have also investigated the MIR
properties of both edge-on galaxies and barred galaxies in our sample. Since
they present similar MIR properties to the other sample galaxies, they do not
influence the MIR properties obtained for the entire sample.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 04:35:15 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Li",
"Haining",
""
],
[
"Wu",
"Hong",
""
],
[
"Cao",
"Chen",
""
],
[
"Zhu",
"Yinan",
""
]
] |
0706.2713 | Bertrand Remy | Udo Baumgartner, Jacqui Ramagge, Bertrand Remy (ICJ) | Contraction groups in complete Kac-Moody groups | null | Groups, Geometry, and Dynamics 2 337-352 (2008) | 10.4171/GGD/43 | null | math.GR | null | Let $G$ be an abstract Kac-Moody group over a finite field and $\bar{G}$ be
the closure of the image of $G$ in the automorphism group of its positive
building. We show that if the Dynkin diagram associated to $G$ is irreducible
and neither of spherical nor of affine type, then the contraction groups of
elements in $\bar{G}$ which are not topologically periodic are not closed. (In
those groups there always exist elements which are not topologically periodic.)
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 04:38:54 GMT"
}
] | 2012-10-04T00:00:00 | [
[
"Baumgartner",
"Udo",
"",
"ICJ"
],
[
"Ramagge",
"Jacqui",
"",
"ICJ"
],
[
"Remy",
"Bertrand",
"",
"ICJ"
]
] |
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