2,291 research outputs found
Quantum information transfer and models for black hole mechanics
General features of information transfer between quantum subsystems, via
unitary evolution, are investigated, with applications to the problem of
information transfer from a black hole to its surroundings. A particularly
direct form of quantum information transfer is "subspace transfer," which can
be characterized by saturation of a subadditivity inequality. We also describe
more general unitary quantum information transfer, and categorize different
models for black hole evolution. Evolution that only creates paired excitations
inside/outside the black hole is shown not to extract information, but
information-transferring models exist both in the "saturating" and
"non-saturating" category. The former more closely capture thermodynamic
behavior; the latter generically have enhanced energy flux, beyond that of
Hawking.Comment: 31 pages, harvmac. v2: nomenclature change, minor added explanation.
v3: small corrections/rewordings; improved figure; version to match
publication in PR
Scalar potential from de Sitter brane in 5D and effective cosmological constant
We derive the scalar potential in zero mode effective action arising from a
de Sitter brane embedded in five dimensions with bulk cosmological constant
. The scalar potential for a scalar field canonically normalized is
given by the sum of exponential potentials. In the case of and
, we point out that the scalar potential has an unstable local
maximum at the origin and exponentially vanishes for large positive scalar
field. In the case of , the scalar potential has an unstable local
maximum at the origin and a stable local minimum, it is shown that the positive
cosmological constant in brane is reduced by negative potential energy of
scalar at minimum.Comment: 14 pages, 5 figures, add the section of cosmological implication
Linking the trans-Planckian and the information loss problems in black hole physics
The trans-Planckian and information loss problems are usually discussed in
the literature as separate issues concerning the nature of Hawking radiation.
Here we instead argue that they are intimately linked, and can be understood as
"two sides of the same coin" once it is accepted that general relativity is an
effective field theory.Comment: 10 pages, 2 figures. Replaced with the version to be published in
General Relativity and Gravitatio
Cutoff AdS/CFT duality and the quest for braneworld black holes
We present significant evidence in favour of the holographic conjecture that
``4D black holes localized on the brane found by solving the classical bulk
equations in are quantum corrected black holes and not classical
ones''. The crucial test is the calculation of the quantum correction to the
Newtonian potential based on a numerical computation of in
Schwarzschild spacetime for matter fields in the zero temperature Boulware
vacuum state. For the case of the conformally invariant scalar field the
leading order term is found to be $M/45\pi r^3$. This result is equivalent to
the result which was previously obtained in the weak-field approximation using
Feynman diagrams and which has been shown to be equivalent, via the AdS/CFT
duality, to the analogous calculation in Randall-Sundrum braneworlds. This
asymptotic behavior was not captured in the analytical approximations for
proposed in the literature. The 4D backreaction equations are then
used to make a prediction about the existence and the possible spacetime
structure of macroscopic static braneworld black holes.Comment: 4 pages, 2 figure
Four Dimensional Black Holes in String Theory
Exact solutions of heterotic string theory corresponding to four-dimensional
charge Q magnetic black holes are constructed as tensor products of an
SU(2)/Z(2Q+2) WZW orbifold with a (0,1) supersymmetric SU(1,1)/U(1) WZW coset
model. The spectrum is analyzed in some detail. ``Bad'' marginal operators are
found which are argued to deform these theories to asymptotically flat black
holes. Surprising behaviour is found for small values of Q, where low-energy
field theory is inapplicable. At the minimal value Q=1, the theory degenerates.
Renormalization group arguments are given that suggest the potential
gravitational singularity of the low-energy field theory is resolved by a
massive two-dimensional field theory. At Q=0, a stable, neutral ``remnant,'' of
potential relevance to the black hole information paradox, is found.Comment: 37 pages + 1 figure (tar compressed and uuencoded
Entropy in Black Hole Pair Production
Pair production of Reissner-Nordstrom black holes in a magnetic field can be
described by a euclidean instanton. It is shown that the instanton amplitude
contains an explicit factor of , where is the area of the event
horizon. This is consistent with the hypothesis that measures the
number of black hole states.Comment: 24 pages (harvmac l mode
Exact Four-Dimensional Dyonic Black Holes and Bertotti-Robinson Spacetimes in String Theory
Conformal field theories corresponding to two-dimensional electrically
charged black holes and to two-dimensional anti-de Sitter space with a
covariantly constant electric field are simply constructed as WZW
coset models. The two-dimensional electrically charged black holes are related
by Kaluza-Klein reduction to the 2+1-dimensional rotating black hole of
Banados, Teitelboim and Zanelli, and our construction is correspondingly
related to its realization as a WZW model. Four-dimensional spacetime solutions
are obtained by tensoring these two-dimensional theories with
coset models. These describe a family of dyonic black holes and the
Bertotti--Robinson universe.Comment: 10 pages, harvmac, (Reference to Kaloper added.
Two-dimensional black holes in accelerated frames: quantum aspects
By considering charged black hole solutions of a one parameter family of two
dimensional dilaton gravity theories, one finds the existence of quantum
mechanically stable gravitational kinks with a simple mass to charge relation.
Unlike their Einsteinian counterpart (i.e. extreme Reissner-Nordstr\"om), these
have nonvanishing horizon surface gravity.Comment: 18 pages, harvmac, 2 figure
Light Sterile Neutrinos in the Supersymmetric U(1)' Models and Axion Models
We propose the minimal supersymmetric sterile neutrino model (MSSNM) where
the sterile neutrino masses are about 1 eV, while the active neutrino masses
and the mixings among the active and sterile neutrinos are generated during
late time phase transition. All the current experimental neutrino data include
the LSND can be explained simultaneously, and the constraints on the sterile
neutrinos from the big bang nucleosynthesis and large scale structure can be
evaded. To realize the MSSNM naturally, we consider the supersymmetric
intermediate-scale U(1)' model, the low energy U(1)' model with a secluded
U(1)'-breaking sector, and the DFSZ and KSVZ axion models. In these models, the
problem can be solved elegantly, and the 1 eV sterile neutrino masses can
be generated via high-dimensional operators. For the low energy U(1)' model
with a secluded U(1)'-breaking sector, we also present a scenario in which the
masses and mixings for the active and sterile neutrinos are all generated
during late time phase transition.Comment: RevTex4, 19 pages, References adde
- …