2,059 research outputs found
Boundary effects on the thermal stability of a black hole at the centre of a conducting spherical shell
This paper reports calculations and analysis of the effects of a perfect
conducting wall of a very large spherical shell on the stable thermodynamic
equilibrium of a black hole sitting at the centre of the shell which is filled
with Electromagnetic blackbody radiation. A parallel is drawn with the case
where electromagnetic is replaced by scalar blackbody radiation with Dirichlet
or Neumann boundary conditions on the wall. It is found that the value of the
shell radius above which only blackbody radiation remains in stable
thermodynamic equilibrium can be considerably affected by vacuum polarization
due to the presence of the wall.Comment: 8 pages, no figure
Fracturing the optimal paths
Optimal paths play a fundamental role in numerous physical applications
ranging from random polymers to brittle fracture, from the flow through porous
media to information propagation. Here for the first time we explore the path
that is activated once this optimal path fails and what happens when this new
path also fails and so on, until the system is completely disconnected. In fact
numerous applications can be found for this novel fracture problem. In the
limit of strong disorder, our results show that all the cracks are located on a
single self-similar connected line of fractal dimension .
For weak disorder, the number of cracks spreads all over the entire network
before global connectivity is lost. Strikingly, the disconnecting path
(backbone) is, however, completely independent on the disorder.Comment: 4 pages,4 figure
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