https://doi.org/10.1140/epjp/s13360-021-01111-w
Regular Article
The gravitino problem in extended gravity cosmologies
1
Dipartimento di Fisica “E. Pancini”, Università di Napoli “Federico II”, Via Cinthia, 80126, Napoli, Italy
2
Istituto Nazionale di Fisica Nucleare (INFN), Sez. di Napoli, Via Cinthia, 80126, Napoli, Italy
3
Scuola Superiore Meridionale, Largo San Marcellino 10, 80138, Napoli, Italy
4
Laboratory for Theoretical Cosmology, Tomsk State University of Control Systems and Radioelectronics (TUSUR), 634050, Tomsk, Russia
5
Dipartimento di Fisica E.R. Cainaiello, University of Salerno, Via Giovanni Paolo II, 84084, Fisciano, SA, Italy
6
INFN, Gruppo Collegato di Salerno, Sezione di Napoli, Via Giovanni Paolo II, 84084, Fisciano, SA, Italy
Received:
24
December
2020
Accepted:
11
January
2021
Published online:
29
January
2021
The gravitino problem is investigated in the framework of extended gravity cosmologies. In particular, we consider f(R) gravity, the most natural extension of the Hilbert–Einstein action, and 
gravity, the extension of teleparallel equivalent gravity. Since in these theories, the expansion laws of the Universe are modified, as compared to the standard 
CDM cosmology, it follows that also the thermal history of particles gets modified. We show that f(R) models allow to avoid the late abundance of gravitinos. In particular, we found that for an appropriate choice of the parameters characterizing the f(R) model, the gravitino abundance turns out to be independent of the reheating temperature. A similar behavior is achieved also in the context of gravity. In this perspective, we can conclude that geometric corrections to standard General Relativity (and to Teleparallel Equivalent of General Relativity) can improve shortcomings both in cosmology and in unified theories beyond the standard model of particles.
Focus Point on Modified Gravity Theories and Cosmology Guest editors: S. Capozziello, V. Gurzadyan.
© The Author(s) 2021
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