17 research outputs found
Thermodynamics of phase transition in higher dimensional AdS black holes
We investigate the thermodynamics of phase transition for
dimensional Reissner Nordstrom (RN)-AdS black holes using a grand canonical
ensemble. This phase transition is characterized by a discontinuity in specific
heat. The phase transition occurs from a lower mass black hole with negative
specific heat to a higher mass black hole with positive specific heat. By
exploring Ehrenfest's scheme we show that this is a second order phase
transition. Explicit expressions for the critical temperature and critical mass
are derived. In appropriate limits the results for dimensional
Schwarzschild AdS black holes are obtained.Comment: LaTex, 11 pages, 5 figures, To appear in JHE
Localization of ultrasound in a three-dimensional elastic network
After exactly half a century of Anderson localization, the subject is more
alive than ever. Direct observation of Anderson localization of electrons was
always hampered by interactions and finite temperatures. Yet, many theoretical
breakthroughs were made, highlighted by finite-size scaling, the
self-consistent theory and the numerical solution of the Anderson tight-binding
model. Theoretical understanding is based on simplified models or
approximations and comparison with experiment is crucial. Despite a wealth of
new experimental data, with microwaves, light, ultrasound and cold atoms, many
questions remain, especially for three dimensions. Here we report the first
observation of sound localization in a random three-dimensional elastic
network. We study the time-dependent transmission below the mobility edge, and
report ``transverse localization'' in three dimensions, which has never been
observed previously with any wave. The data are well described by the
self-consistent theory of localization. The transmission reveals non-Gaussian
statistics, consistent with theoretical predictions.Comment: Final published version, 5 pages, 4 figure
Simulation of the Hydrogen Ground State in Stochastic Electrodynamics-2: Inclusion of Relativistic Corrections
In a recent paper the authors studied numerically the hydrogen ground state in stochastic electrodynamics (SED) within the the non-relativistic approximation. In quantum theory the leading non-relativistic corrections to the ground state energy dominate the Lamb shift related to the photon cloud that should cause the quantum-like behaviour of SED. The present work takes these corrections into account in the numerical modelling. It is found that they have little effect; the self-ionisation that occurs without them remains present. It is speculated that the point-charge approximation for the electron is the cause of the failure