Vacuum Polarization Effects in the Global Monopole Spacetime in the   Presence of Wu-Yang Magnetic Monopole
  In this paper we consider the presence of the Wu-Yang magnetic monopole in the global monopole spacetime and their influence on the vacuum polarization effects around these two monopoles placed together. According to Wu-Yang [Nucl. Phys. {\bf B107}, 365 (1976)] the solution of the Klein-Gordon equation in such an external field will not be an ordinary function but, instead, {\it section}. Because of the peculiar radial symmetry of the global monopole spacetime, it is possible to cover its space section by two overlapping regions, needed to define the singularity free vector potential, and to study the quantum effects due to a charged scalar field in this system. In order to develop this analysis we construct the explicit Euclidean scalar Green {\it section} associated with a charged massless field in a global monopole spacetime in the presence of the Abelian Wu-Yang magnetic monopole. Having this Green section it is possible to study the vacuum polarization effects. We explicitly calculate the renormalized vacuum expectation value $<\Phi(x)^*\Phi(x) >_{Ren.}$, associated with a charged scalar field operator and the respective energy-momentum tensor,   $<T_{\mu\nu}(x)>_{Ren.}$, which are expressed in terms of the parameter which codify the presence of the global and magnetic monopoles. 
E. R. Bezerra de Mello