1,178 research outputs found
Euler Chern Simons Gravity from Lovelock Born Infeld Gravity
In the context of a gauge theoretical formulation, higher dimensional gravity
invariant under the AdS group is dimensionally reduced to Euler-Chern-Simons
gravity. The dimensional reduction procedure of Grignani-Nardelli [Phys. Lett.
B 300, 38 (1993)] is generalized so as to permit reducing D-dimensional Lanczos
Lovelock gravity to d=D-1 dimensions.Comment: 6 pages, no figures, accepted for publication in Phys. Lett.
The superstring Hagedorn temperature in a pp-wave background
The thermodynamics of type IIB superstring theory in the maximally
supersymmetric plane wave background is studied. We compute the thermodynamic
partition function for non-interacting strings exactly and the result differs
slightly from previous computations. We clarify some of the issues related to
the Hagedorn temperature in the limits of small and large constant RR 5-form.
We study the thermodynamic behavior of strings in the case of geometries in the presence of NS-NS and RR 3-form backgrounds. We
also comment on the relationship of string thermodynamics and the thermodynamic
behavior of the sector of Yang-Mills theory which is the holographic dual of
the string theory.Comment: 22 pages, JHEP style, minor misprints corrected, some comments adde
Strongly coupled 't Hooft model on the lattice
A lattice strong coupling calculation of the spectrum and chiral condensate
of the 't Hooft model is presented. The agreement with the results of the
continuum theory is strikingly good even at the fourth order in the strong
coupling expansion.Comment: LATTICE99(Spin Models), talk presented by F. Berruto, 3 pages, LaTex,
espcrc2.st
New Penrose Limits and AdS/CFT
We find a new Penrose limit of AdS_5 x S^5 giving the maximally
supersymmetric pp-wave background with two explicit space-like isometries. This
is an important missing piece in studying the AdS/CFT correspondence in certain
subsectors. In particular whereas the Penrose limit giving one space-like
isometry is useful for the SU(2) sector of N=4 SYM, this new Penrose limit is
instead useful for studying the SU(2|3) and SU(1,2|3) sectors. In addition to
the new Penrose limit of AdS_5 x S^5 we also find a new Penrose limit of AdS_4
x CP^3.Comment: 30 page
Mean Field Theory of Josephson Junction Arrays with Charge Frustration
Using the path integral approach, we provide an explicit derivation of the
equation for the phase boundary for quantum Josephson junction arrays with
offset charges and non-diagonal capacitance matrix. For the model with nearest
neighbor capacitance matrix and uniform offset charge , we determine,
in the low critical temperature expansion, the most relevant contributions to
the equation for the phase boundary. We explicitly construct the charge
distributions on the lattice corresponding to the lowest energies. We find a
reentrant behavior even with a short ranged interaction. A merit of the path
integral approach is that it allows to provide an elegant derivation of the
Ginzburg-Landau free energy for a general model with charge frustration and
non-diagonal capacitance matrix. The partition function factorizes as a product
of a topological term, depending only on a set of integers, and a
non-topological one, which is explicitly evaluated.Comment: LaTex, 24 pages, 8 figure
Entropy of the self-dual string soliton
We compute the entropy and the corresponding central charge of the self-dual
string soliton in the supergravity regime using the blackfold description of
the fully localized M2-M5 intersection.Comment: 15 pages, 1 figure, harvma
Lattice Gauge Theories and the Heisenberg Antiferromagnetic Chain
We study the strongly coupled 2-flavor lattice Schwinger model and the
SU(2)-color QCD_2. The strong coupling limit, even with its inherent
nonuniversality, makes accurate predictions of the spectrum of the continuum
models and provides an intuitive picture of the gauge theory vacuum. The
massive excitations of the gauge model are computable in terms of spin-spin
correlators of the quantum Heisenberg antiferromagnetic spin-1/2 chain.Comment: Proceedings LATTICE99 (spin models), 3 page
Higher dimensional gravity invariant under the AdS group
A higher dimensional gravity invariant both under local Lorentz rotations and
under local Anti de Sitter boosts is constructed. It is shown that such a
construction is possible both when odd dimensions and when even dimensions are
considered. It is also proved that such actions have the same coefficients as
those obtained by Troncoso and Zanelli.Comment: 5 pages, no figures; final version to appear in Phys. Lett.
Time-Dependent Open String Solutions in 2+1 Dimensional Gravity
We find general, time-dependent solutions produced by open string sources
carrying no momentum flow in 2+1 dimensional gravity. The local Poincar\'e
group elements associated with these solutions and the coordinate
transformations that transform these solutions into Minkowski metric are
obtained. We also find the relation between these solutions and the planar wall
solutions in 3+1 dimensions.Comment: CU-TP-619, 18 pages. (minor changes
String-Inspired Gravity Coupled to Yang-Mills Fields
String-inspired 1+1-dimensional gravity is coupled to Yang-Mills fields in
the Cangemi-Jackiw gauge-theoretical formulation, based on the extended
Poincar\'e group. A family of couplings, which involves metrics obtainable from
the physical metric with a conformal rescaling, is considered, and the
resulting family of models is investigated both at the classical and the
quantum level. In particular, also using a series of Kirillov-Kostant phases,
the wave functionals that solve the constraints are identified.Comment: 15 pages, LaTex
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