Casimir energy for a three-piece relativistic string

Journal Article · Fri Mar 01 04:00:00 EST 1996 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.53.3224· OSTI ID:279210

Brevik, I ^[1]; Nielsen, H B ^[2]; Odintsov, S D ^[3]

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1. Applied Mechanics, The Norwegian Institute of Technology, N-7034 Trondheim (Norway)
2. The Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen O/ (Denmark)
3. Departament dEstructura i Constituents de la Materia (DECM), Facultad de Fisica, Universidad de Barcelona, Diagonal 647, E-08028 Barcelona (Spain)

The Casimir energy for the transverse oscillations of a piecewise uniform closed string is calculated. The string consists of three pieces I, II, III of equal length, endowed with different tensions and mass densities, but adjusted in such a way that the velocity of sound always equals the velocity of light. In this sense the string forms a relativistic mechanical system. In the present paper the string is subjected to the following analysis: the dispersion function is derived and the zero-point energy is regularized using (i) a contour integration technique, being most convenient for the generalization of the theory to the case of finite temperatures, and (ii) the Hurwitz {zeta}-function technique, being usually the most compact method when the purpose is to calculate the Casimir energy numerically at {ital T}=0. The energy, being always nonpositive, is shown graphically in some cases as functions of the tension ratios I/II and II/III. The generalization to finite temperature theory is also given. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 279210
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 6 Vol. 53; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CASIMIR EFFECT
DISPERSIONS
ENERGY
OSCILLATIONS
STRING MODELS
TEMPERATURE DEPENDENCE