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تسجيل مستخدم جديدSelf-similar cosmological solutions in f(R,T) gravity theory
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We study the $f(R,T)$ cosmological models under the self-similarity hypothesis. We determine the exact form that each physical and geometrical quantity may take in order that the Field Equations (FE) admit exact self-similar solutions through the matter collineation approach. We study two models: the case$ f(R,T)=f_{1}(R)+f_{2}(T)$ and the case $f(R,T)=f_{1}(R)+f_{2} (R)f_{3}(T)$. In each case, we state general theorems which determine completely the form of the unknown functions $f_{i}$ such that the field equations admit self-similar solutions. We also state some corollaries as limiting cases. These results are quite general and valid for any homogeneous self-similar metric$.$ In this way, we are able to generate new cosmological scenarios. As examples, we study two cases by finding exact solutions to these particular models.
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The recent article entitled Cosmological inviability of $f(R,T)$ gravity [Phys. Rev. D 95 (2017) 123536], by H. Velten and T.R.P. Caram^es, claims that the reference A transition from a decelerated to an accelerated phase of the universe expansion fr
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