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8. K. T. Phelps. A general product construction for error corre cting codes. SIAM J. |
Algebraic Discrete Methods , 5(2):224–228, 1984. |
9. K. T. Phelps. A product construction for perfect codes over a rbitrary alphabets. |
IEEE Trans. Inf. Theory , 30(5):769–771, 1984. |
10. V. N. Potapov and D. S. Krotov. On the number of n-ary quasigroups of finite order. |
Submitted. ArXiv:0912.5453 |
11. V.N.PotapovandD.S.Krotov. Asymptoticsforthenumbero fn-quasigroupsoforder |
4.Sib. Math. J. , 47(4):720–731, 2006. DOI: 10.1007/s11202-006-0083-9 tran slated |
from Sib. Mat. Zh. 47(4) (2006), 873-887. ArXiv:math/0605104 |
O. Heden |
Department of Mathematics, KTH |
S-100 44 Stockholm, Sweden |
email:[email protected] |
D. Krotov |
Sobolev Institute of Mathematics |
and |
Mechanics and Mathematics Department, Novosibirsk State Univer sity |
Novosibirsk, Russia |
email:[email protected] |
8 |
arXiv:1001.0002v2 [hep-th] 9 Mar 2010Gravity duals for logarithmic conformal field theories |
Daniel Grumiller and Niklas Johansson |
Institute for Theoretical Physics, Vienna University of Te chnology |
Wiedner Hauptstrasse 8-10/136, A-1040 Vienna, Austria |
E-mail:[email protected], [email protected]. ac.at |
Abstract. Logarithmic conformal fieldtheories with vanishingcentra l charge describe systems |
withquencheddisorder, percolation ordiluteself-avoidi ngpolymers. Inthesetheories theenergy |
momentum tensor acquires a logarithmic partner. In this tal k we address the construction of |
possible gravity duals for these logarithmic conformal fiel d theories and present two viable |
candidates for such duals, namely theories of massive gravi ty in three dimensions at a chiral |
point. |
Outline |
Thistalk isorganized asfollows. Insection 1werecall sali ent featuresof2-dimensionalconformal |
field theories. In section 2 we review a specific class of logar ithmic conformal field theories where |
the energy momentum tensor acquires a logarithmic partner. In section 3 we present a wish-list |
for gravity duals to logarithmic conformal field theories. I n section 4 we discuss two examples |
of massive gravity theories that comply with all the items on that list. In section 5 we address |
possible applications of an Anti-deSitter/logarithmic co nformal field theory correspondence in |
condensed matter physics. |
1. Conformal field theory distillate |
Conformal field theories (CFTs) are quantum field theories th at exhibit invariance under angle |
preserving transformations: translations, rotations, bo osts, dilatations and special conformal |
transformations. In two dimensions the conformal algebra i s infinite dimensional, and thus |
two-dimensional CFTs exhibit a particularly rich structur e. They arise in various contexts in |
physics, including string theory, statistical mechanics a nd condensed matter physics, see e.g. [1]. |
The main observables in any field theory are correlation func tions between gauge invariant |
operators. There exist powerful tools to calculate these co rrelators in a CFT. The operator |
content of various CFTs may differ, but all CFTs contain at leas t an energy momentum tensor |
Tµν. Conformal invariance requires the energy momentum tensor to be traceless, Tµ |
µ= 0, |
in addition to its conservation, ∂µTµν= 0. In lightcone gauge for the Minkowski metric, |
ds2= 2dzd¯z, these equations take a particularly simple form: Tz¯z= 0,Tzz=Tzz(z) :=OL(z) |
andT¯z¯z=T¯z¯z(¯z) :=OR(¯z). Conformal Ward identities determine essentially unique ly the form |
of 2- and3-point correlators between thefluxcomponents OL/Rof theenergy momentum tensor:∝an}b∇acketle{tOR(¯z)OR(0)∝an}b∇acket∇i}ht=cR |
2¯z4(1a) |
∝an}b∇acketle{tOL(z)OL(0)∝an}b∇acket∇i}ht=cL |
2z4(1b) |
∝an}b∇acketle{tOL(z)OR(0)∝an}b∇acket∇i}ht= 0 (1c) |
∝an}b∇acketle{tOR(¯z)OR(¯z′)OR(0)∝an}b∇acket∇i}ht=cR |
¯z2¯z′2(¯z−¯z′)2(1d) |
∝an}b∇acketle{tOL(z)OL(z′)OL(0)∝an}b∇acket∇i}ht=cL |
z2z′2(z−z′)2(1e) |
∝an}b∇acketle{tOL(z)OR(¯z′)OR(0)∝an}b∇acket∇i}ht= 0 (1f) |
∝an}b∇acketle{tOL(z)OL(z′)OR(0)∝an}b∇acket∇i}ht= 0 (1g) |
The real numbers cL,cRare the left and right central charges, which determine key p roperties of |
the CFT. We have omitted terms that are less divergent in the n ear coincidence limit z,¯z→0 as |
well as contact terms, i.e., contributions that are localiz ed (δ-functions and derivatives thereof). |
If someone provides us with a traceless energy momentum tens or and gives us a prescription |
how to calculate correlators,1but does not reveal whether the underlying field theory is a CF T, |
thenwecanperformthefollowing check. Wecalculate all 2- a nd3-point correlators of theenergy |
momentum tensor with itself, and if at least one of the correl ators does not match precisely with |
the corresponding correlator in (1) then we know that the fiel d theory in question cannot be a |
CFT. On the other hand, if all the correlators match with corr esponding ones in (1) we have |
non-trivial evidence that the field theory in question might be a CFT. Let us keep this stringent |
check in mind for later purposes, but switch gears now and con sider a specific class of CFTs, |
namely logarithmic CFTs (LCFTs). |
2. Logarithmic CFTs with an energetic partner |
LCFTs were introduced in physics by Gurarie [2]. We focus now on some properties of LCFTs |
and postpone a physics discussion until the end of the talk, s ee [3,4] for reviews. There are two |
conceptually different, but mathematically equivalent, way s to define LCFTs. In both versions |
there exists at least one operator that acquires a logarithm ic partner, which we denote by Olog. |
We focus in this talk exclusively on theories where one (or bo th) of the energy momentum |
tensor flux components is the operator acquiring such a partn er, for instance OL. We discuss |
now briefly both ways of defining LCFTs. |
According to the first definition “acquiring a logarithmic pa rtner” means that the |
Hamiltonian Hcannot be diagonalized. For example |
H/parenleftbigg |
Olog |
OL/parenrightbigg |
=/parenleftbigg |
2 1 |
0 2/parenrightbigg/parenleftbigg |
Olog |
OL/parenrightbigg |
(2) |
Theangularmomentum operator Jmay ormay not bediagonalizable. Weconsider onlytheories |
whereJis diagonalizable: |
J/parenleftbigg |
Olog |
OL/parenrightbigg |