M. Bordag et K. Kirsten, VACUUM ENERGY IN A SPHERICALLY SYMMETRICAL BACKGROUND FIELD, Physical review. D. Particles and fields, 53(10), 1996, pp. 5753-5760
The vacuum energy of a scalar field in a spherically symmetric backgro
und field is considered. It is expressed through the Jest function of
the corresponding scattering problem. The renormalization is discussed
in detail and performed using the uniform asymptotic expansion of the
Jest function. The method is demonstrated in a simple explicit exampl
e.