Gott-Kaiser-Stebbins (GKS) e ect in an accelerated expanding universe

We want to nd the cosmological constant in uence on cosmic microwave background (CMB) temperature due to moving linear cosmic strings. Using the space- time metric of a linear cosmic string in an accelerated expanding universe, the Gott- Kaiser-Stebbins (GKS) e ect, as an important mechanism in producing temperature discontinuity in the (CMB), is considered; then, its modi cation due to the e ect of the cosmological constant is calculated. The result shows that a positive cosmological constant (i.e. the presence of cosmic strings in an accelerated expanding universe) weakens the discontinuity in temperature so that a stronger resolution is needed to detect the corresponding in uences on the CMB power spectrum and anisotropy.