29489956
Direct mode summation for the Casimir energy of a solid ball
The Casimir energy of a solid ball placed in an infinite medium is calculated by a direct frequency summation using the contour integration. It is assumed that the permittivity and permeability of the ball and medium satisfy the condition . After deriving the general expression for the Casimir energy, a compact ball is considered when . Calculations are carried out which are of the first order in and take account of the fifth-order terms in the uniform asymptotic expansion of the Bessel functions involved. The implication of the results to attempt to explain sonoluminescence via the Casimir effect is briefly discussed.
204934704
Some recent results in calculating the Casimir energy at zero and finite temperature
The survey summarizes briefly the results obtained recently in the Casimir effect studies considering the following subjects: i) account of the material characteristics of the media and their influence on the vacuum energy (for example, dilute dielectric ball); ii) application of the spectral geometry methods for investigating the vacuum energy of quantized fields with the goal to gain some insight, specifically, in the geometrical origin of the divergences that enter the vacuum energy and to develop the relevant renormalization procedure; iii) universal method for calculating the high temperature dependence of the Casimir energy in terms of heat kernel coefficients.
15884859
Casimir energy of a nonuniform string
The Casimir energy of a non-uniform string built up from two pieces with different speed of sound is calculated. A standard procedure of subtracting the energy of an infinite uniform string is applied, the subtraction being interpreted as the renormalization of the string tension. It is shown that in the case of a homogeneous string this method is completely equivalent to the zeta renormalization.
199675867
SOME RECENT RESULTS IN CALCULATION OF THE CASIMIR ENERGY AT ZERO AND FINITE TEMPERATURE
123132132
The Model of the relativistic particle with curvature and torsion
The (2+1)-dimensional model of the relativistic particle, described by the action with a linear dependence on the curvature and torsion of a particle world trajectory, is investigated. Massive, massless and tachyonic states are shown to be generally present in the model. For all three mass sectors the solutions of classical equations of motion are constructed. Depending on the values of the model parameters, the quantization of the system leads to the unitary irreducible representations of the universal covering group of SL(2,R) of either the discrete series Dγ±, γ > 0 or the principal series Cσϑ, σ ⪖ 14, ϑ ϵ [1, 1). The quantum spectrum and the wave functions of the physical states of the system are found.
17711121
Boundary conditions at spatial infinity for fields in Casimir calculations
The importance of imposing proper boundary conditions for fields at spatial infinity in the Casimir calculations is elucidated.
125434188
RPA description of dipole oscillations in deformed sodium clusters
121516467
CollectiveEλ excitations of surface character in spherical and deformed sodium clusters: vibrating potential model
The self-consistent vibrating potential model (VPM) is extended for the description ofEλ surface collective excitations in alkali metal clusters with practically any kind of static deformation. The case of spherical clusters is also covered. Any single-particle potentials and valence electron densities for which the coefficients of the multipole expansion are known can be used within the model. The strength function method incorporated into the model allows one to avoid solving the equations for every state and, as a result, simplifies the calculations drastically. The model is of a quite general character and can also be used for description of giant resonances in atomic nuclei if the Coulomb terms are neglected. The VPM is applied to calculate theE1,E2 andE3 excitations in spherical (Na8, Na20 and Na40) and deformed (Na10, Na18 and Na26) clusters.
117583655
Overlap of metal clusters and nuclear structure physics
118802177
Vibrating potential model for giant resonances in deformed metal clusters and atomic nuclei
The vibrating potential model is extended to provide a description of giant resonances in metal clusters and atomic nuclei with any kind of deformation.
123206973
The interior of the charge transition density and the structure of low-lying states in deformed nuclei
The RPA calculations of charge transition densities (CTD) rho lambda mu nu (r) for the E2 transitions from the ground state to the low-lying Ipi Knu =2+2nu and 2+0nu states in 164Dy predict rather strong peaks of single-particle nature in the interior of the CTD. A simple explanation of the results is given. The reliability of the results obtained, their possible application to the study of the structure of low-lying states and some predictions for nuclei of the rare-earth region are discussed.