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Related papers: On the entropy of a spherical plasma shell

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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…

High Energy Physics - Theory · Physics 2017-11-01 K. A. Milton , Pushpa Kalauni , Prachi Parashar , Yang Li

It has been recognized for some time that even for perfect conductors, the interaction Casimir entropy, due to quantum/thermal fluctuations, can be negative. This result was not considered problematic because it was thought that the…

Quantum Physics · Physics 2021-03-05 Yang Li , Kimball A. Milton , Prachi Parashar , Lujun Hong

We calculate the Casimir energy and entropy for two spheres described by the perfect metal model, plasma model, and Drude model in the large separation limit. We obtain nonmonotonic behavior of the Helmholtz free energy with separation and…

Statistical Mechanics · Physics 2015-05-28 Pablo Rodriguez-Lopez

Not only are Casimir interaction entropies not guaranteed to be positive, but also, more strikingly, Casimir self-entropies of bodies can be negative. Here, we attempt to interpret the physical origin and meaning of these negative…

High Energy Physics - Theory · Physics 2024-05-28 Yang Li , Kimball A. Milton , Prachi Parashar , Gerard Kennedy , Nima Pourtolami , Xin Guo

Continuing the discussion on negative entropy in Casimir-effect like configurations, we consider two simple one-dimensional examples. One is the s-wave contribution to a plasma sphere and the other a single delta function potential. Some…

Quantum Physics · Physics 2018-07-30 M. Bordag

Recently the Casimir self-entropy of an electromagnetic $\delta$-function shell was considered by two different groups, with apparently discordant conclusions, although both had concluded that a region of negative entropy existed for…

High Energy Physics - Theory · Physics 2019-02-27 Kimball A. Milton , Pushpa Kalauni , Prachi Parashar , Yang Li

Collisionless plasmas exhibit nonthermal particle distributions after being energized; as a consequence, they enter a state of low Boltzmann-Gibbs (BG) entropy relative to the thermal state. The Vlasov equations predict that in a…

High Energy Astrophysical Phenomena · Physics 2022-07-21 Vladimir Zhdankin

We compute the Casimir Energy of a spherical region using a Surface Impedance approach. We characterize the Surface Impedance of the boundary using plasma model. Exact analytical formulae are obtained by means of the zeta function…

High Energy Physics - Theory · Physics 2012-11-20 Luigi Rosa

Casimir entropies due to quantum fluctuations in the interaction between electrical bodies can often be negative, either caused by dissipation or by geometry. Although generally such entropies vanish at zero temperature, consistent with the…

High Energy Physics - Theory · Physics 2016-10-19 Yang Li , K. A. Milton , Pushpa Kalauni , Prachi Parashar

Negative entropy has been known in Casimir systems for some time. For example, it can occur between parallel metallic plates modeled by a realistic Drude permittivity. Less well known is that negative entropy can occur purely geometrically,…

Quantum Physics · Physics 2015-05-14 K. A. Milton , Romain Guérout , Gert-Ludwig Ingold , Astrid Lambrecht , Serge Reynaud

We discuss the Casimir effect between two identical, parallel slabs, emphasizing the role of dissipation and temperature. Starting from quite general assumptions, we analyze the behavior of the Casimir entropy in the limit T->0 and link it…

Quantum Physics · Physics 2009-11-13 F. Intravaia , C. Henkel

We calculate the Casimir energy and entropy for two perfect metal spheres in the large and short separation limit. We obtain nonmonotonic behavior of the Helmholtz free energy with separation and temperature, leading to parameter ranges…

Quantum Physics · Physics 2014-01-28 Pablo Rodriguez-Lopez

It has been increasingly becoming clear that Casimir and Casimir-Polder entropies may be negative in certain regions of temperature and separation. In fact, the occurrence of negative entropy seems to be a nearly ubiquitous phenomenon. This…

We calculate the entropy and the temperature dependent part of the free energy for a free standing plane plasma sheet and for the a free standing plane slab of finite thickness with dispersion described by the plasma model. In case the…

Quantum Physics · Physics 2018-10-17 M. Bordag

Negative values of the Casimir entropy occur quite frequently at low temperatures in arrangements of metallic objects. The physical reason lies either in the dissipative nature of the metals as is the case for the plane-plane geometry or in…

Casimir entropy is an important aspect of casimir effect.In this paper,we employ the path integral method to derive the total relation for casimir entropy and internal energy of arbitrary shaped objects in the presence of two,three and four…

Quantum Physics · Physics 2017-01-05 Marjan Jafari

The Casimir stress on a spherical shell in de Sitter background for massless scalar field satisfying Dirichlet boundary conditions on the shell is calculated. The metric is written in conformally flat form. Although the metric is time…

General Relativity and Quantum Cosmology · Physics 2009-10-31 M. R. Setare , R. Mansouri

We calculate the Casimir interaction between a sphere and a plate, both described by the plasma model, the Drude model, or generalizations of the two models. We compare the results at both zero and finite temperatures. At asymptotically…

Statistical Mechanics · Physics 2015-05-18 Roya Zandi , Thorsten Emig , Umar Mohideen

In the present paper we investigate thermal fluctuation corrections to the vacuum energy at zero temperature of a conformally coupled massless scalar field whose modes propagate in the Einstein universe with a spherical boundary,…

High Energy Physics - Theory · Physics 2022-11-18 Herondy F. S. Mota , Celio R. Muniz , Valdir B. Bezerra

In this work we consider the dynamical Casimir effect for a massless scalar field -- under Dirichlet boundary conditions -- between two concentric spherical shells. We obtain a general expression for the average number of particle creation,…

Quantum Physics · Physics 2009-11-13 F. Pascoal , L. C. Céleri , S. S. Mizrahi , M. H. Y. Moussa
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