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.
Big bounce cosmology for Palatini R 2 gravity with a Nieh–Yan term / Bombacigno, F.; Montani, G.. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - 79:5(2019). [10.1140/epjc/s10052-019-6918-x]
Big bounce cosmology for Palatini R 2 gravity with a Nieh–Yan term
Bombacigno F.Primo
;Montani G.Ultimo
2019
Abstract
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.File | Dimensione | Formato | |
---|---|---|---|
Bombacigno_Big-bounce_2019.pdf
accesso aperto
Tipologia:
Documento in Post-print (versione successiva alla peer review e accettata per la pubblicazione)
Licenza:
Tutti i diritti riservati (All rights reserved)
Dimensione
216.79 kB
Formato
Adobe PDF
|
216.79 kB | Adobe PDF |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.