Casimir entropy is an important aspect of casimir effect and at the nanoscale is visible. In this paper, we employ the path integral method to ‎obtain a‎ ‎general‎ relation for casimir entropy and ‎i‎nternal energy of arbitrary shaped objects in the presence of two, three and four dimension scalar fields and ‎the‎ electromagnetic field. For this purpose, using Lagrangian and based on a perturb...

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 the geometric form of the objects involved. Examples for the latter are the sphere-plane and the sphere-sphere geometry, where negative Casimir entropies ca...

The classical ‘Kirchhoff’s theorem’ (the energy density of the radiation at equilibrium at high temperature, T , is a function of T only) is used to obtain the Casimir energy at zero temperature without recourse to regularization. The validity of ‘Kirchhoff’s theorem’ at the high-temperature limit for the case at hand is confirmed. The Casimir entropy is defined and its temperature dependence i...

Quantities associated with Casimir forces are calculated in a model wave system of one spatial dimension where the physical ideas are transparent and the calculations allow easy numerical evaluation. The calculations show strong dependence upon fixedor free-end (Dirichlet or Neumann) boundary conditions for waves on a one-dimensional string, analogous to infinitely-conducting or infinitely-perm...

We generalize the results of hep-th/0008140 to the case of the (n+ 1)-dimensional closed FRW universe satisfying a general equation of state of the form p = wρ. We find that the entropy of the universe can no longer be expressed in a form similar to the Cardy formula, when w 6= 1/n. As a result, in general the entropy formula does not coincide with the Friedmann equation when the conjectured bo...

The problem with the temperature dependence of the Casimir force is investigated. Specifically, the entropy behavior in the low temperature limit, which caused debates in the literature, is analyzed. It is stressed that the behavior of the relaxation frequency in the T-->0 limit does not play a physical role since the anomalous skin effect dominates in this range. In contrast with the previous ...

We analyze the high temperature (or classical) limit of the Casimir effect (for various massless fields). A simple physical argument suggests that the Casimir energy (as opposed to the Casimir free energy) should vanish in the classical limit. We check the validity of this argument for massless scalar field confined in a cavity with boundaries of arbitrary shape, using path integral formalism. ...

We review recent results obtained in the physics of the thermal Casimir force acting between two dielectrics, dielectric and metal, and between metal and semiconductor. The detailed derivation for the low-temperature behavior of the Casimir free energy, pressure and entropy in the configuration of two real dielectric plates is presented. For dielectrics with finite static dielectric permittivit...

The Cardy-Verlinde formula is further verified by using the Kerr-NewmanAdS4 and Kerr-Newman-dS4 black holes. In the Kerr-Newman-AdS4 spacetime, we find that, for strongly coupled CFTs with AdS duals, to cast the entropy of the CFT into the Cardy-Verlinde formula the Casimir energy must contains the terms −n ( JΩH + QΦ 2 + QΦ0 2 ) , which associate with rotational and electric potential energies...