4,488 research outputs found
Probing black holes in non-perturbative gauge theory
We use a 0-brane to probe a ten-dimensional near-extremal black hole with N
units of 0-brane charge. We work directly in the dual strongly-coupled quantum
mechanics, using mean-field methods to describe the black hole background
non-perturbatively. We obtain the distribution of W boson masses, and find a
clear separation between light and heavy degrees of freedom. To localize the
probe we introduce a resolving time and integrate out the heavy modes. After a
non-trivial change of coordinates, the effective potential for the probe agrees
with supergravity expectations. We compute the entropy of the probe, and find
that the stretched horizon of the black hole arises dynamically in the quantum
mechanics, as thermal restoration of unbroken U(N+1) gauge symmetry. Our
analysis of the quantum mechanics predicts a correct relation between the
horizon radius and entropy of a black hole.Comment: 30 pages, LaTeX, 8 eps figures. v2: references added. v3: more
reference
Before the Seminoles: Football at Florida State College, 1902-1904
When Coach W. W. Hughes looked out at his football team in the autumn of 1902, he was under no pressure to improve on the previous year’s season. Recently hired to teach Latin at Florida State College (FSC), Professor Hughes had played football at Vanderbilt University and, when he arrived in Tallahassee, had volunteered to coach FSC’s fledgling team. Practicing on the newly graded gridiron west of campus (a renovated cow pasture), the FSC Eleven prepared for their first game against a city team from nearby Bainbridge, Georgia. Hughes, pleased with the team’s progress, anticipated success
Matrix embeddings on flat and the geometry of membranes
We show that given three hermitian matrices, what one could call a fuzzy
representation of a membrane, there is a well defined procedure to define a set
of oriented Riemann surfaces embedded in using an index function defined
for points in that is constructed from the three matrices and the point.
The set of surfaces is covariant under rotations, dilatations and translation
operations on , it is additive on direct sums and the orientation of the
surfaces is reversed by complex conjugation of the matrices. The index we build
is closely related to the Hanany-Witten effect. We also show that the surfaces
carry information of a line bundle with connection on them.
We discuss applications of these ideas to the study of holographic matrix
models and black hole dynamics.Comment: 41 pages, 3 figures, uses revtex4-1. v2: references added, corrected
an error in attribution of idea
Thermal diffractive corrections to Casimir energies
We study the interplay of thermal and diffractive effects in Casimir
energies. We consider plates with edges, oriented either parallel or
perpendicular to each other, as well as a single plate with a slit. We compute
the Casimir energy at finite temperature using a formalism in which the
diffractive effects are encoded in a lower dimensional non-local field theory
that lives in the gap between the plates. The formalism allows for a clean
separation between direct or geometric effects and diffractive effects, and
makes an analytic derivation of the temperature dependence of the free energy
possible. At low temperatures, with Dirichlet boundary conditions on the
plates, we find that diffractive effects make a correction to the free energy
which scales as T^6 for perpendicular plates, as T^4 for slits, and as T^4 log
T for parallel plates.Comment: 31 pages, 7 figures, LaTeX. v2: minor typos fixed, version to appear
in PR
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