6,273 research outputs found
Thermodynamics of Two-Dimensional Black-Holes
We explore the thermodynamics of a general class of two dimensional dilatonic
black-holes. A simple prescription is given that allows us to compute the mass,
entropy and thermodynamic potentials, with results in agreement with those
obtained by other methods, when available.Comment: 12 page
Conformal Operators for Partially Massless States
The AdS/CFT correspondence is explored for ``partially massless'' fields in
AdS space (which have fewer helicity states than a massive field but more than
a conventional massless field). Such fields correspond in the boundary
conformal field theory to fields obeying a certain conformally-invariant
differential equation that has been described by Eastwood et al. The first
descendant of such a field is a conformal field of negative norm. Hence,
partially massless fields may make more physical sense in de Sitter as opposed
to Anti de Sitter space.Comment: 14 page
A WZW model based on a non-semi-simple group
We present a conformal field theory which desribes a homogeneous four
dimensional Lorentz-signature space-time. The model is an ungauged WZW model
based on a central extension of the Poincar\'e algebra. The central charge of
this theory is exactly four, just like four dimensional Minkowski space. The
model can be interpreted as a four dimensional monochromatic plane wave. As
there are three commuting isometries, other interesting geometries are expected
to emerge via duality.Comment: 8 pages, phyzzx, IASSNS-HEP-93/61 Texable versio
Measurements of critical current diffraction patterns in annular Josephson junctions
We report systematic measurements of the critical current versus magnetic
field patterns of annular Josephson junctions in a wide magnetic field range. A
modulation of the envelope of the pattern, which depends on the junction width,
is observed. The data are compared with theory and good agreement is found.Comment: 4 pages, 5 figure
Current distribution in a parallel configuration superconducting strip-line detector
Superconducting detectors based on parallel microscopic strip-lines are promising candidates for single molecule detection in time-of-flight mass spectrometry. The device physics of this configuration is complex. In this letter, we employ nano-optical techniques to study the variation of current density, count rate, and pulse amplitude transversely across the parallel strip device. Using the phenomenological London theory, we are able to correlate our results to a non-uniform current distribution between the strips, governed by the London magnetic penetration depth. This fresh perspective convincingly explains anomalous behaviour in large area parallel superconducting strip-line detectors reported in previous studies
The Ramond-Ramond self-dual Five-form's Partition Function on the Ten Torus
In view of the recent interest in formulating a quantum theory of
Ramond-Ramond p-forms, we exhibit an SL(10,Z) invariant partition function for
the chiral four-form of Type IIB string theory on the ten-torus. We follow the
strategy used to derive a modular invariant partition function for the chiral
two-form of the M-theory fivebrane. We also generalize the calculation to
self-dual quantum fields in spacetime dimension 2p=2+4k, and display the
SL(2p,Z) automorphic forms for odd p>1. We relate our explicit calculation to a
computation of the B-cycle periods, which are discussed in the work of Witten.Comment: 18 page
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