The Gott-Kaiser-Stebbins (GKS) Effect in an Accelerated Expanding Universe

TL;DR

This paper investigates how a positive cosmological constant affects the Gott-Kaiser-Stebbins effect caused by cosmic strings, showing it weakens temperature discontinuities in the CMB within an accelerated universe.

Contribution

It provides a modified calculation of the GKS effect considering the cosmological constant, revealing its impact on CMB temperature discontinuities.

Findings

Positive cosmological constant weakens GKS temperature discontinuity

More sensitive measurements needed to detect the effect

Implications for CMB anisotropy analysis

Abstract

We want to find the cosmological constant influence on cosmic microwave background (CMB) temperature due to moving linear cosmic strings. Considering the space-time metric of a linear cosmic string in an accelerated expanding universe, the Gott-Kaiser-Stebbins (GKS) effect, as an important mechanism in producing temperature discontinuity in the CMB, is considered and its modification due to the effect 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 more strong resolution is needed to detect the corresponding influences on the CMB power spectrum and anisotropy.