چکیده
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Here we consider a flat FRWuniverse whose horizon entropy meets the R´enyi entropy of nonextensive
systems. In our model, the ordinary energy-momentum conservation law is not always valid. By applying
the Clausius relation as well as the Cai-Kim temperature to the apparent horizon of a flat FRWuniverse, we
obtain modified Friedmann equations. Fitting the model to the observational data on the current accelerated
universe, some values for the model parameters are also addressed. Our study shows that the current
accelerating phase of universe expansion may be described by a geometrical fluid, originated from the
nonextensive aspects of geometry, which models a varying dark energy source interacting with the matter
field in the Rastall way. Moreover, our results indicate that the probable nonextensive features of spacetime
may also be used to model a varying dark energy source which does not interact with the matter field and is
compatible with the current accelerated phase of the Universe.
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