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arXiv · 1707.09840

Casimir Self-Entropy of a Spherical Electromagnetic $\delta$-Function Shell

K. A. Milton·Pushpa Kalauni·Prachi Parashar·Yang Li
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Abstract

In this paper we continue our program of computing Casimir self-entropies of idealized electrical bodies. Here we consider an electromagnetic $\delta$-function sphere ("semitransparent sphere") whose electric susceptibility has a transverse polarization with arbitrary strength. Dispersion is incorporated by a plasma-like model. In the strong coupling limit, a perfectly conducting spherical shell is realized. We compute the entropy for both low and high temperatures. The TE self-entropy is negative as expected, but the TM self-entropy requires ultraviolet and infrared subtractions, and, surprisingly, is only positive for sufficiently strong coupling. Results are robust under different regularization schemes.

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K. A. Milton, Pushpa Kalauni, Prachi Parashar, Yang Li. 2017-07-31. Casimir Self-Entropy of a Spherical Electromagnetic $\delta$-Function Shell. https://doi.org/10.1103/physrevd.96.085007

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