CLASSICAL AND QUANTUM GRAVITY, vol.14, no.12, pp.3215-3224, 1997 (Journal Indexed in SCI)
We study the interaction of a massless quantized spinor field with the gravitational field of N parallel static cosmic strings by using a perturbative approach. We show that the presence of more than one cosmic string gives rise to an additional contribution to the energy density of vacuum fluctuations, thereby leading to a vacuum force of attraction between two parallel cosmic strings.