64 research outputs found
A New Phase at Finite Quark Density from AdS/CFT
We explore phases of N=2 super Yang-Mills theory at finite quark density by
introducing quark chemical potential in a D3-D7 setup. We formulate the
thermodynamics of brane embeddings and find that we need to renormalize the
finite chemical potential due to the divergence of the thermodynamic potentials
and we find that the density versus chemical potential equation of state has
rich structure. This yields two distinct first order phase transitions in a
small window of quark density. In order words, there is a new first order phase
transition in the region of deconfined quarks. In this new phase, the chemical
potential is a decreasing function of the density. We suggest that this might
be relevant to the difference in sQGP--wQGP phases of QCD.Comment: 4 pages, revte
Inhomogeneous Structures in Holographic Superfluids: II. Vortices
We study vortex solutions in a holographic model of Herzog, Hartnoll, and
Horowitz, with a vanishing external magnetic field on the boundary, as is
appropriate for vortices in a superfluid. We study relevant length scales
related to the vortices and how the charge density inside the core of the
vortex behaves as a function of temperature or chemical potential. We extract
the critical superfluid velocity from the vortex solutions, study how it
behaves as a function of the temperature, and compare it to earlier studies and
to the Landau criterion. We also comment on the possibility of a
Berezinskii-Kosterlitz-Thouless vortex confinement-deconfinement transition.Comment: 32 pages, 10 figures, typos corrected, references adde
Tensor Minkowski Functionals for random fields on the sphere
We generalize the translation invariant tensor-valued Minkowski Functionals
which are defined on two-dimensional flat space to the unit sphere. We apply
them to level sets of random fields. The contours enclosing boundaries of level
sets of random fields give a spatial distribution of random smooth closed
curves. We obtain analytic expressions for the ensemble expectation values for
the matrix elements of the tensor-valued Minkowski Functionals for isotropic
Gaussian and Rayleigh fields. We elucidate the way in which the elements of the
tensor Minkowski Functionals encode information about the nature and
statistical isotropy (or departure from isotropy) of the field. We then
implement our method to compute the tensor-valued Minkowski Functionals
numerically and demonstrate how they encode statistical anisotropy and
departure from Gaussianity by applying the method to maps of the Galactic
foreground emissions from the PLANCK data.Comment: 1+23 pages, 5 figures, Significantly expanded from version 1. To
appear in JCA
D-branes in 2d Lorentzian black hole
We study D-branes in the Lorentzian signature 2D black hole string theory. We
use the technique of gauged WZW models to construct the associated boundary
conformal field theories. The main focus of this work is to discuss the
(semi-classical) world-volume geometries of the D-branes. We also discuss
comparison of our work with results in related gauged WZW models.Comment: 24 pages, 5 figures, uses JHEP3.cl
Revisiting the Thermal AdS partition function
We rewrite the worldsheet torus partition function of the Thermal AdS CFT by
isolating the boundary parameters. Using this, we show that the spectrum of the
Euclidean BTZ black hole and Lorentzian AdS3 can be extracted -- the latter as
a zero temperature limit. A similar procedure recovers the Lorentzian BTZ
spectrum proposed in an earlier work. We then use our expression to construct a
boundary modular invariant expression as a Poincar\'e series
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