Related papers: Holography, Entropy and Extra Dimensions

We consider general black hole solutions in five-dimensional spacetime in the presence of a negative cosmological constant. We obtain a cosmological evolution via the gravity/gauge theory duality (holography) by defining appropriate…

Black holes whose near-horizon geometries are locally, but not necessarily globally, AdS$_3$ (three-dimensional anti-de Sitter space) are considered. Using the fact that quantum gravity on AdS$_3$ is a conformal field theory, we…

Various two-dimensional O(N) models coupled to Euclidean quantum gravity, whose intrinsic dimension is four, are shown to belong to universality classes of nongravitating statistical models in a lower number of dimensions. It is speculated…

In a Randall-Sundrum theory (RS1) 3+1 dimensional black holes and higher dimensional black holes are not the natural continuations of each other. 3+1 dimensional black holes decay into a large number of 4+1 dimensional black holes at a…

We investigate the microscopic origin of black hole entropy, in particular the gap between the maximum entropy of ordinary matter and that of black holes. Using curved space, we construct configurations with entropy greater than their area…

The maximum entropy that can be stored in a bounded region of space is in dispute: it goes as volume, implies (non-gravitational) microphysics; it goes as the surface area, asserts the "holographic principle." Here I show how the…

We consider the effects of higher curvature terms on a holographic dual description of boundary conformal field theory. Specifically, we consider three-dimensional gravity with a specific combination of Ricci tensor square and curvature…

Holography suggests a considerable reduction of degrees of freedom in theories with gravity. However it seems to be difficult to understand how holography could be realized in a closed re--contracting universe. In this letter we claim that…

Using a holographic proposal for the geometric entropy we study its behavior in the geometry of Schwarzschild black holes in global $AdS_p$ for $p=3,4,5$. Holographically, the entropy is determined by a minimal surface. On the gravity side,…

Quantum Geometry (the modern Loop Quantum Gravity using graphs and spin-networks instead of the loops) provides microscopic degrees of freedom that account for the black-hole entropy. However, the procedure for state counting used in the…

Theories with infinite volume extra dimensions open exciting opportunities for particle physics. We argued recently that along with attractive features there are phenomenological difficulties in this class of models. In fact, there is no…

We calculated the entropy of a class of inhomogeneous dust universes. Allowing spherical symmetry, we proposed a holographic principle by reflecting all physical freedoms on the surface of the apparent horizon. In contrast to flat…

We study the evolution and scaling of the entanglement entropy after two types of quenches for a 2+1 field theory, using holographic techniques. We study a thermal quench, dual to the addition of a shell of uncharged matter to four…

We study the entanglement entropy in confining theories with gravity duals using the holographic prescription of Ryu and Takayanagi. The entanglement entropy between a region and its complement is proportional to the minimal area of a bulk…

In statistical mechanics entropy is a measure of disorder obeying Boltzmann's formula $S=\log{\cal N}$, where ${\cal N}$ is the accessible phase space volume. In black hole thermodynamics one associates to a black hole an entropy…

I review some of the concepts at the crossroads of gravitational thermodynamics, holography and quantum mechanics. First, the origin of gravitational thermodynamics due to coarse graining of quantum information is exemplified using the…

Four-dimensional magnetic black holes including dilaton and abelian gauge fields which are solutions of supergravity can also be obtained by dimensional reduction of the Einstein-Maxwell gravity in five dimensions. In the extremal case the…

One of the most dramatic consequences of low-scale (~1 TeV) quantum gravity in models with large or warped extra dimension(s) is copious production of mini black holes at future colliders and in ultra-high-energy cosmic ray collisions.…

Holographic space-time, a theory of quantum gravity that generalizes string theory and quantum field theory, predicts black holes in the early matter-dominated era of its models of inflation. Before these black holes can decay, there is a…

On the basis of a number of Swampland conditions, we argue that the Hilbert space of baby universe states must be one-dimensional in a consistent theory of quantum gravity. This scenario may be interpreted as a type of "Gauss's law for…