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Edi Halyo

Publications and source records attributed to Edi Halyo.

At least 19 recordsLinked to original sources

A Model for Unitary Black Hole Evaporation

We describe a model for unitary black hole evaporation with no information loss in terms of a quantum computation. We assume that there is a fine tuned interaction between the qubits of the black hole Bell states which is the inverse of premeasurement. Evaporation is unitary due to a projection on the black hole state at the end of each computation whereas information comes out of the black hole by teleportation. The model requires only four operations; the qubit interactions, the Hadamard and CNOT gates and the projection which is nonunitary. The model is a concrete quantum computation that realizes the final black hole state idea with some modifications.

hep-th

Are Near $AdS_2$ Spacetimes Dual to $AdS_2$ Black Holes?

We claim that there is a one to one correspondence between $NAdS_2$ spacetimes and dilatonic $AdS_2$ black holes. We show that these have the same thermodynamics and can be described by the same states of 1D CFTs with the same central charge. In addition, we show that these are actually the same set of solutions since a field redefinition in the Schwarzian theory transforms its equation of motion into the time independent part of the bulk Einstein equation. The deformations of the $AdS_2$ boundary as a function of the boundary time are exactly the conformal factor of the $AdS_2$ black hole metric as a function of the radial bulk coordinate.

hep-th

The Cardy Formula from Goldstone Bosons

Two dimensional conformal field theories, can be described by their pseudo Goldstone bosons when the conformal symmetry is spontaneously and anomalously broken. We show that the Schwarzian action of these bosons leads to the Cardy formula without using modular invariance. As a result, the Cardy formula applies to conformal field theories on a cylinder and chiral theories in one dimension. This also explains why the Cardy--Verlinde formula for theories on $S^1 \times S^{d-2}$ can be written in the form of the Cardy formula of an effective two dimensional theory.

hep-th

Computing Black Hole Entropy at Infinity

We show that the entropy of asymptotically flat, nonextremal black holes can be computed at infinity. We provide a prescription for transforming these black holes to $AdS_2$ black holes with the same entropy by dimensional reduction to 2D and a Weyl transformation. We apply our prescription to Schwarzschild, 4D Reissner--Nordstrom and generic nonextremal black holes. In the transformed coordinates, the asymptotic regions contain a global $AdS_2$ whose entropy can be computed either as the holographic entanglement entropy or as the entanglement entropy of a pair of Rindler $AdS_2$ spaces in the thermofield double state. This precisely reproduces the entropy of the original nonextremal black holes.

hep-th

Black Hole Entropy and the Pseudo Goldstone Bosons of Conformal Symmetry

The very near horizon regions of nonextremal black holes have a conformal symmetry which is anomalous and spontaneously broken by the Rindler vacuum. Therefore, these black holes can effectively be described by the pseudo Goldstone bosons of conformal symmetry and their Schwarzian action which is determined by the breakdown of the conformal symmetry to $SL(2)$. In Euclidean gravity, the Schwarzian action leads to the Wald entropy of nonextremal black holes. These results are consistent with the neutral limit of near extremal charged black holes described by near $AdS_2$ space--times.

hep-th

Schwarzschild Black Holes and Asymptotic $AdS_2$

We show that the entropy of D--dimensional Schwarzschild black holes are given by the entanglement entropy of a boundary of global $AdS_2$ space that lives at asymptotic infinity. We dimensionally reduce General Relativity to two dimensions which leads to 2D dilatonic gravity which has black hole solutions with the same thermodynamics as D--dimensional Schwarzschild black holes. These dilatonic black holes can be transformed into certain $AdS_2$ black holes by Weyl transformations which are symmetries of the theory that preserve the thermodynamics. In the asymptotic limit, the $AdS_2$ black holes become global $AdS_2$ which can be described by two entangled $AdS_2$ Rindler spaces. The entanglement entropy of a single $AdS_2$ Rindler space reproduces the Schwarzschild black hole entropy.

hep-th

The Holographic Entanglement Entropy of Schwarzschild Black Holes

We show that Schwarzschild black hole metrics are, asymptotically, Weyl equivalent to $AdS_2 \times S^{D-2}$ where the spherical factor is the horizon. The holographic entanglement entropy of $AdS_2$ exactly reproduces the Schwarzschild black hole entropy which implies that black hole degrees of freedom live at asymptotic infinity. In generalized theories of gravity, the same procedure reproduces Wald entropy.

hep-th

Liouville Theory on Horizons: Towards a Quantum Theory of Black Holes

We show that any nonextremal black hole can be described by a Liouville theory that lives on its very near horizon region. In classical Liouville theory, the black hole corresponds to a field configuration that reproduces the Rindler metric. In quantum Liouville theory, the black hole state in the CFT is created by the puncture operator that gives rise to a conical singularity with a deficit angle of $2 π$. This state is "heavy" with a nonnormalizable wave function in the minisuperspace approximation. Black hole entropy counts the number of ways the "heavy" black hole state can be obtained by acting with a product of "light, quantum" operators in the CFT. Black hole hair is described by the "background charge" in the CFT but its physical nature is unclear.

hep-th

Complexity Near Horizons

We generalize the concept of complexity near horizons to all nondegenerate black holes. For Schwarzschild black holes, we show that Rindler observers see a complexity change of $S$ during proper time $1/κ$ which corresponds to the creation of a causal patch with proper length $1/κ$ inside the horizon. We attempt to describe complexity in the horizon CFT and the Euclidean picture.

hep-th

Extremal Black Hole Entropy from Horizon Conformal Field Theories

We show that the entropy of extremal $D=4$ Reissner--Nordstrom black holes can be computed from horizon CFTs with central charges and conformal weights fixed by the dimensionless Rindler energy. This is possible in the simultaneous extremal and near horizon limit of the black hole which takes the geometry to an $AdS_2$ Rindler space with finite temperature. The CFT description of dilatonic $AdS_2$ black holes, obtained from extremal ones by dimensional reduction, lead to exactly the same CFT states.

hep-th

Horizon Conformal Field Theories from $AdS_2$ Black Holes

We show that the very near horizon region of nonextreme black holes, which can be described by horizon CFTs, are related to $AdS_2$ Rindler spaces. The latter are $AdS_2$ black holes with specific masses and can be described by states of either $D=1$ or $D=2$ CFTs. The central charges of these CFTs and the conformal weights of their states that correspond to the nonextreme black holes exactly match those predicted by the horizon CFTs, providing supporting evidence for this description.

hep-th

Black Holes as Conformal Field Theories on Horizons

We show that any nonextreme black hole can be described by a state with $L_0=E_R$ in a $D=2$ chiral conformal field theory with central charge $c=12E_R$ where $E_R$ is the dimensionless Rindler energy of the black hole. The theory lives in the very near horizon region, i.e. around the origin of Rindler space. Black hole hair is the momentum along the Euclidean dimensionless Rindler time direction. As evidence, we show that $D$--dimensional Schwarzschild black holes and $D=2$ dilatonic ones that are obtained from them by spherical reduction are described by the same conformal field theory states.

hep-th

On the Holographic Nature Of Rindler Energy

We show that the dimensionless Rindler energy of a black hole, $E_R$, is exactly the surface Hamiltonian obtained from the Einstein--Hilbert action evaluated on the horizon. Therefore, $E_R$ is given by a surface integral over the horizon and manifestly holographic. In the context of the AdS/CFT duality, Rindler energy corresponds, on the boundary, to a dimensionless energy given by the product of the AdS radius and the extensive part of the CFT energy. We find that, beyond General Relativity, $E_R$ is still holographic but not necessarily given by the surface Hamiltonian of the theory.

hep-th

Rindler Energy is Wald Entropy

We show that, in any theory of gravity, the entropy of any nonextreme black hole is given by $2 πE_R$ where $E_R$ is the dimensionless Rindler energy. Separately, we show that $E_R$ is exactly Wald's Noether charge and therefore this entropy is identical to Wald entropy. However, it is off--shell and derived solely from the time evolution of the black hole. We examine Gauss--Bonnet black holes as an example and speculate on the degrees of freedom that $E_R$ counts.

hep-th

Entropic Gravity in Rindler Space

We show that Rindler horizons are entropic screens and gravity is an entropic force in Rindler space by deriving the Verlinde entropy formula from the focusing of light due to a mass close to the horizon. Consequently, gravity is also entropic in the near horizon regions of Schwarzschild and de Sitter space-times. In different limits, the entropic nature of gravity in Rindler space leads to the Bekenstein entropy bound and the uncertainty principle.

hep-th

Supersymmetry Breaking by the Right-Handed Tau Neutrino

We describe supersymmetry breaking by the F-term of a heavy right-handed tau neutrino with a VEV. Due to the the tau neutrino Yukawa coupling, the neutralino, chargino and scalar mass matrices and the weak currents are modified. In addition, there are new cubic and quartic scalar and trilinear R parity violating interactions. For large $\tan β$ these effects may be quite large. The scenario requires low energy supersymmetry breaking with generic values of $F \sim 10^{10}$~GeV.

hep-ph

Metastable Supersymmetry Breaking and Minimal Gauge Mediation on Branes

We construct a model with D5 branes wrapped on a deformed and resolved $A_6$ singularity which realizes metastable supersymmetry breaking and minimal gauge mediation. Supersymmetry is broken at tree level by the F--term of singlet which also obtains a VEV as required in gauge mediation. Three nodes of the singularity are used to break supersymmetry whereas the other three realize gauge mediation. The supersymmetry breaking scale is suppressed due to brane instanton effects which are computed using a geometric transition.

hep-th

Solitons on Singularities

We describe solitons that live on the world--volumes of D5 branes wrapped on deformed $A_2$ singularities fibered over $C(x)$. We show that monopoles are D3 branes wrapped on a node of the deformed singularity and stretched along $C(x)$. F and D--term strings are D3 branes wrapped on a node of a singularity that is deformed and resolved respectively. Domain walls require deformed $A_3$ singularities and correspond to D5 branes wrapped on a node and stretched along $C(x)$.

hep-th