Euclidean scalar Green function in a higher dimensional global monopole space–time

Abstract

We construct the explicit Euclidean scalar Green function associated with a massless field in a higher dimensional global monopole space–time, i.e., a (1+d)-space–time with d⩾3 which presents a solid angle deficit. Our result is expressed in terms of an infinite sum of products of Legendre functions with Gegenbauer polynomials. Although this Green function cannot be expressed in a closed form, for the specific case where the solid angle deficit is very small, it is possible to develop the sum and obtain the Green function in a more workable expression. Having this expression it is possible to calculate the vacuum expectation value of some relevant operators. As an application of this formalism, we calculate the renormalized vacuum expectation value of the square of the scalar field, 〈Φ2(x)〉Ren, and the energy-momentum tensor, 〈Tμν(x)〉Ren, for the global monopole space–time with spatial dimensions d=4 and d=5.