Damghan University Press Iranian Journal of Astronomy and Astrophysics 2322-4924 2 2 2015 12 01 Gott-Kaiser-Stebbins (GKS) effect in an accelerated expanding universe عنوان 121 125 23 10.22128/ijaa.2015.23 EN S. Y. Rokni Department of Physics, University of Qom, Qom, I. R. Iran; H. Razmi Department of Physics, University of Qom, Qom, I. R. Iran; M. R. Bordbar Department of Physics, University of Qom, Qom, I. R. Iran; Journal Article 2016 01 16 <span>We</span><span>want</span><span>to</span><span>find</span><span>the</span><span>cosmological</span><span>constant</span><span>influence</span><span>on</span><span>cosmic</span><span>microwave</span><span>background</span><span>(</span><span>CMB</span><span>)</span><span>temperature</span><span>due</span><span>to</span><span>moving</span><span>linear</span><span>cosmic</span><span>strings.</span><span>Using</span><span>the</span><span>space-time</span><span>metric</span><span>of</span><span>a</span><span>linear</span><span>cosmic</span><span>string</span><span>in</span><span>an</span><span>accelerated</span><span>expanding</span><span>universe,</span><span>the</span><span>Gott-Kaiser Stebbins</span><span>(GKS)</span><span>e</span><span>ff</span><span>ect,</span><span>as</span><span>an</span><span>important</span><span>mechanism</span><span>in</span><span>producing</span><span>temperature</span><span>discontinuity</span><span>in</span><span>the</span><span>(</span><span>CMB</span><span>),</span><span>is</span><span>considered;</span><span>then,</span><span>its</span><span>modification</span><span>due</span><span>to</span><span>the</span><span>e</span><span>ff</span><span>ect</span><span>of</span><span>the</span><span>cosmological</span><span>constant</span><span>is</span><span>calculated.</span><span>The</span><span>result</span><span>shows</span><span>that</span><span>a</span><span>positive</span><span>cosmological</span><span>constant</span><span>(i.e.</span><span>the</span><span>presence</span><span>of</span><span>cosmic</span><span>strings</span><span>in</span><span>an</span><span>accelerated</span><span>expanding</span><span>universe)</span><span>weakens</span><span>the</span><span>discontinuity</span><span>in</span><span>temperature</span><span>so</span><span>that</span><span>a</span><span>stronger</span><span>resolution</span><span>is</span><span>needed</span><span>to</span><span>detect</span><span>the</span><span>corresponding</span><span>influences</span><span>on</span><span>the</span><span>CMB</span><span>power</span><span>spectrum</span><span>and</span><span>anisotropy.</span> https://ijaa.du.ac.ir/article_23_41c49803a287b4c475876bb9191fc865.pdf