Wightman functions in de Sitter and anti-de Sitter spacetimes in the   presence of cosmic string
  In this paper we evaluate the Wightman functions associated with a massive quantum scalar field in de Sitter and anti-de Sitter spacetimes in the presence of a cosmic string. Having these functions we calculate the corresponding renormalized vacuum expectation values of the field squared and present the behavior of the contributions induced by the cosmic string as function of the proper distance to it for different values of the parameter which codify the presence of this linear topological defect. 
Eug\^enio R. Bezerra de Mello
hep-th