Ground State Energy of Massive Scalar Field in the Background of Finite Thickness Cosmic String

摘要

We calculate the ground state energy of a massive scalar field in thebackground of a cosmic string of finite thickness (Gott-Hiscock metric). Usingzeta functional regularization we discuss the renormalization and the relevantheat kernel coefficients in detail. The finite (non local) part of the groundstate energy is calculated in 2+1 dimensions in the approximation of a smallmass density of the string. By a numerical calculation it is shown to vanish asa function of the radius of the string and of the parameter $\xi$ of thenonconformal coupling.