15584

13939

كارشناسي ارشد

ذرات بنيادي و نظريه ميدان ها

اصفهان : دانشگاه صنعتي اصفهان

1398

نه، 122 ص. : نمودار.

بهروز ميرزا

احمد شيرزاد

فرهنگ لران، سروش شاكري

1399/03/31

كتابنامه

فيزيك

فيزيك

1399/03/31

2617205

Investigation of the generalized Friedmann equations based on Renyi entropy and gravity in the presence of torsion using dynamical systems approach Mahnaz Izadi mahnaz izadi@ph iut ac ir january 19 2020 Department of Physics Isfahan University of Technology Isfahan 84156 83111 Iran University Code IUT 77142 Degree M S c Language Farsisupervisor Dr Behrouz Mirzab mirza@iut ac irAbstract In this thesis we explain how to obtain Friedmann equations first by using theory of general relativity and then by considering the Beckstein Hawking entropy as the cosmic entropy and applying the first law of thermodynamics to the apparent horizon Then with considering Renyi entropy as the entropy of the apparent horizon and applying the Clausius relation modified Friedmann equations has been obtained in the Renyi cosmology Then with dynamical system approach it has been shown that the obtained additional terms compared to the standard Friedmann equations may describe the current accelerated universe In the final chapter of this thesis we explain how to obtain Friedmann equations in the presence of the torsion field using Einstein Cartan theory We have also studied the evolution of these equations using the dynamical system approach in both cases of weak and constant torsion field Keywords Cosmology Dynamical systems The First law of thermodynamics Generalized Friedman equations Torsion field

بهروز ميرزا

احمد شيرزاد

فرهنگ لران، سروش شاكري