179 research outputs found
Nonlocal black hole evaporation and quantum metric fluctuations via inhomogeneous vacuum density
Inhomogeneity of the actual value of the vacuum energy density is considered
in a black hole background. We examine the back-reaction of a Schwarzschild
black hole to the highly inhomogeneous vacuum density, and argue the
fluctuations lead to deviations from general relativity in the near-horizon
region. In particular, we found that vacuum fluctuations onto the horizon
trigger adiabatic release of quantum information, while vacuum fluctuations in
the vicinity of the horizon produce potentially observable metric fluctuations
of order the Schwarzschild radius. Consequently, we propose a form of strong
nonviolent nonlocality in which we simultaneously get nonlocal release of
quantum information, and observable metric fluctuations.Comment: 10 pages, REVTeX 4.1, 2 figures. Published in the Special Issue
"Classical and Quantum Approaches to Black Holes" of Advances in High Energy
Physic
Entropic Entanglement: Information Prison Break
We argue certain nonviolent local quantum field theory (LQFT) modification
considered at the global horizon () of a static spherically-symmetric
black hole can lead to adiabatic leakage of quantum information in the form of
Hawking particles. The source of the modification is (i) smooth at and
(ii) rapidly vanishing at . Furthermore, we restore the unitary
evolution by introducing extra quanta which departs slightly from the generic
Hawking emission without changing the experience of an infalling observer (no
drama). Also, we suggest that a possible interpretation of the
Bekenstein-Hawking bound as entanglement entropy may yield a nonsingular
dynamical horizon behavior described by black hole thermodynamics. Hence by
treating gravity as a field theory, and considering its coupling to the matter
fields in the Minkowski vacuum, we derive the conjectured fluctuations of the
background geometry of a black hole.Comment: 16 pages, 2 figures. Published in Advances in High Energy Physic
Magnetic-field and doping dependence of low-energy spin fluctuations in the antiferroquadrupolar compound Ce(1-x)La(x)B(6)
CeB(6) is a model compound exhibiting antiferroquadrupolar (AFQ) order, its
magnetic properties being typically interpreted within localized models. More
recently, the observation of strong and sharp magnetic exciton modes forming in
its antiferromagnetic (AFM) state at both ferromagnetic and AFQ wave vectors
suggested a significant contribution of itinerant electrons to the spin
dynamics. Here we investigate the evolution of the AFQ excitation upon the
application of an external magnetic field and the substitution of Ce with
non-magnetic La, both parameters known to suppress the AFM phase. We find that
the exciton energy decreases proportionally to T_N upon doping. In field, its
intensity is suppressed, while its energy remains constant. Its disappearance
above the critical field of the AFM phase is preceded by the formation of two
modes, whose energies grow linearly with magnetic field upon entering the AFQ
phase. These findings suggest a crossover from itinerant to localized spin
dynamics between the two phases, the coupling to heavy-fermion quasiparticles
being crucial for a comprehensive description of the magnon spectrum.Comment: Extended version with a longer introduction and an additional figure.
6 pages and 5 figure
Ternary algebras and groups
We construct explicitly groups associated to specific ternary algebras which
extend the Lie (super)algebras (called Lie algebras of order three). It turns
out that the natural variables which appear in this construction are variables
which generate the three-exterior algebra. An explicit matrix representation of
a group associated to a peculiar Lie algebra of order three is constructed
considering matrices with entry which belong to the three exterior algebra.Comment: 11 pages contribution to the 5th International Symposium on Quantum
Theory and Symmetries (QTS5
Orbifold Singularities, Lie Algebras of the Third Kind (LATKes), and Pure Yang-Mills with Matter
We discover the unique, simple Lie Algebra of the Third Kind, or LATKe, that
stems from codimension 6 orbifold singularities and gives rise to a kind of
Yang-Mills theory which simultaneously is pure and contains matter. The root
space of the LATKe is 1-dimensional and its Dynkin diagram consists of one
point. The uniqueness of the LATKe is a vacuum selection mechanism.Comment: 42 pages; version appearing in JM
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