Bruno Sanna | Searcharxiv

arXiv2021

The Trans-Planckian Censorship Conjecture in different frameworks of viable inflation

We review the recently proposed Trans-Planckian Censorship Conjecture that stems from the Trans-Planckian problem of cosmological perturbations. We analyze the implications and constraints that TCC introduces in different frameworks of viable inflation. We revisit the case of slow-roll scalar field inflation and we investigate the cases of slow-roll $f(R)$ and $f(R,ϕ)$-gravity. Finally, we consider the conjecture in the context of constant-roll scalar field inflation.

gr-qc↗

arXiv2021

Bounce Models within Teleparallel modified gravity

In this paper, working in a Friedman-Lemaitre-Robertson-Walker (FLRW), first, in the flat case, we recover the generalized Friedman equation of Quantum Loop cosmology, and therefore the cosmological bounce, in the framework of modified teleparallel gravity $f(T)$-model, $T$ being the torsion scalar introduced in teleparallel gravity approach, without invoking unconventional exotic matter. Furthermore we study the associated perturbations again in a flat FLRW space-time. Then, we generalize the results to the curved FLRW space-time, where some issues related to the choice of tetrad exist, by using an appropriate formulation. In this context, the results of Born-Infeld model are also investigated.

gr-qc↗