35,456 research outputs found
Exotic phase separation in one-dimensional hard-core boson system with two- and three-body interactions
We investigate the ground state phase diagram of hard-core boson system with
repulsive two-body and attractive three-body interactions in one-dimensional
optic lattice. When these two interactions are comparable and increasing the
hopping rate, physically intuitive analysis indicates that there exists an
exotic phase separation regime between the solid phase with charge density wave
order and superfluid phase. We identify these phases and phase transitions by
numerically analyzing the density distribution, structure factor of
density-density correlation function, three-body correlation function and von
Neumann entropy estimator obtained by density matrix renormalization group
method. These exotic phases and phase transitions are expected to be observed
in the ultra-cold polar molecule experiments by properly tuning interaction
parameters, which is constructive to understand the physics of ubiquitous
insulating-superconducting phase transitions in condensed matter systems
Real-time Correlators and Hidden Conformal Symmetry in Kerr/CFT Correspondence
In this paper, we study the real-time correlators in Kerr/CFT, in the low
frequency limit of generic non-extremal Kerr(-Newman) black holes. From the low
frequency scattering of Kerr-Newman black holes, we show that for the uncharged
scalar scattering, there exists hidden conformal symmetry on the solution
space. Similar to Kerr case, this suggests that the Kerr-Newman black hole is
dual to a two-dimensional CFT with central charges and
temperatures .
Using the Minkowski prescription, we compute the real-time correlators of
charged scalar and find perfect match with CFT prediction. We further discuss
the low-frequency scattering of photons and gravitons by Kerr black hole and
find that their retarded Green's functions are in good agreement with CFT
prediction. Our study supports the idea that the hidden conformal symmetry in
the solution space is essential to Kerr/CFT correspondence.Comment: 15 pages, Latex; typos corrected, references updated; minor
correction, published versio
R\'enyi Mutual Information for Free Scalar in Even Dimensions
We compute the R\'enyi mutual information of two disjoint spheres in free
massless scalar theory in even dimensions higher than two. The spherical twist
operator in a conformal field theory can be expanded into the sum of local
primary operators and their descendants. We analyze the primary operators in
the replicated scalar theory and find the ones of the fewest dimensions and
spins. We study the one-point function of these operators in the conical
geometry and obtain their expansion coefficients in the OPE of spherical twist
operators. We show that the R\'enyi mutual information can be expressed in
terms of the conformal partial waves. We compute explicitly the R\'enyi mutual
information up to order , where is the cross ratio and is the
spacetime dimension.Comment: 29 pages; More discussion on the partition function of primary
operators, the contribution from spin-1 operator has been correcte
Hidden Conformal Symmetry and Quasi-normal Modes
We provide an algebraic way to calculate the quasi-normal modes of a black
hole, which possesses a hidden conformal symmetry. We construct an infinite
tower of quasi-normal modes from the highest-weight mode, in a simple and
elegant way. For the scalar, the hidden conformal symmetry manifest itself in
the fact that the scalar Laplacian could be rewritten in terms of the
quadratic Casimir. For the vector and the tensor, the hidden conformal symmetry
acts on them through Lie derivatives. We show that for three-dimensional black
holes, with appropriate combination of the components the radial equations of
the vector and the tensor could be written in terms of the Lie-induced
quadratic Casimir. This allows the algebraic construction of the quasi-normal
modes feasible. Our results are in good agreement with the previous study.Comment: 23 pages; references added; typos corrected, more clarifications,
published versio
Strong Subadditivity and Emergent Surface
In this paper, we introduce two bounds which we call the Upper Differential
Entropy and the Lower Differential Entropy for an infinite family of
intervals(strips) in quantum field theory. The two bounds are equal provided
that the theory is translational invariant and the entanglement entropy varies
smoothly with respect to the interval. When the theory has a holographic dual,
strong subadditivity of entanglement entropy indicates that there is always an
emergent surface whose gravitational entropy is exactly given by the bound.Comment: 18 pages, 8 figures, replace "residual entropy" to "differential
entropy
The Complexity of Testing Monomials in Multivariate Polynomials
The work in this paper is to initiate a theory of testing monomials in
multivariate polynomials. The central question is to ask whether a polynomial
represented by certain economically compact structure has a multilinear
monomial in its sum-product expansion. The complexity aspects of this problem
and its variants are investigated with two folds of objectives. One is to
understand how this problem relates to critical problems in complexity, and if
so to what extent. The other is to exploit possibilities of applying algebraic
properties of polynomials to the study of those problems. A series of results
about and polynomials are obtained in this paper,
laying a basis for further study along this line
Note on DBI dynamics of Dbrane Near NS5-branes
In this note, we investigate the homogeneous radial dynamics of (Dp,
NS5)-systems without and with one compactified transverse direction, in the
framework of DBI effective action. During the homogeneous evolution, the
electric field on the D-brane is always conserved and the radial motion could
be reduced to an one-dimension dynamical system with an effective potential.
When the Dp-brane energy is not high, the brane moves in a restricted region,
with the orbits depending on the conserved energy, angular momentum through the
form of the effective potential. When the Dp-brane energy is high enough, it
can escape to the infinity. It turns out that the conserved angular momentum
plays an interesting role in the dynamics. Moreover, we discuss the gauge
dynamics around the tachyon vacuum and find that the dynamics is very
reminiscent of the string fluid in the rolling tachyon case.Comment: 13 pages, 2 figures; typos corrected, discussions improved; gauge
dynamics has been include
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