https://doi.org/10.1140/epjc/s10052-019-6918-x
Regular Article - Theoretical Physics
Big bounce cosmology for Palatini 
gravity with a Nieh–Yan term
1
Physics Department, “Sapienza” University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy
2
ENEA, FSN-FUSPHY-TSM, R.C. Frascati, Via E. Fermi 45, 00044, Frascati, Italy
* e-mail: flavio.bombacigno@uniroma1.it
Received:
26
October
2018
Accepted:
3
May
2019
Published online:
14
May
2019
We analyze the cosmological implementation of Palatini f(R) theories, constructed with a Nieh–Yan term and solved with respect to the torsion. We consider the relevant case of the quadratic correction to the Hilbert–Palatini action in the Ricci scalar, mimicking the Starobinsky model of the metric formulation. We point out the emergence of peculiar cosmological scenarios, depending on the sign of such correction, able to reproduce bouncing settings and to restore the standard Universe dynamics in the late asymptotic limit. Furthermore, we outline the settling of Little-Rip dynamics, which calls for a deeper investigation in order to be regularized via matter creation. Finally, we also show that in our model the Immirzi field is asymptotically frozen in time, resembling the morphology of Loop Quantum Gravity standard formulation.
© The Author(s), 2019
