Two quantum field theories whose Hilbert spaces do not overlap cannot transmit a signal to
one another. From this simple principle, we deduce some highly nontrivial consequences for …

We study the bounce cosmology to construct a singularity-free f (R) model using the
reconstruction technique. The formulation of the f (R) model is based on the Raychaudhari …

We show that the f (R)-gravity theories with constant Ricci scalar in the Jordan/Einstein
frame can be described by Einstein or Einstein–Maxwell gravity with a cosmological term …

We investigate the dynamics of f (R) gravity in Jordan and Einstein frames. First, we perform
a phase-space singularities analysis in both frames. We show that, typically, anisotropic …

The present paper reports a study on the bouncing behavior of the viscous modified
Chaplygin gas (MCG) in Einstein as well as modified gravity framework. For a bouncing …

We use the Jordan frame–Einstein frame correspondence to explore dual universes with
contrasting cosmological evolutions. We study the mapping between Einstein and Jordan …

In this work, we present some cosmologically relevant solutions using the spatially flat
Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime in metric f (R) gravity where the …

In the present work we present the full treatment of scalar and vector cosmological
perturbations in a non-singular bouncing universe in the context of metric f (R) cosmology …

We show that the $ f (R) $-gravity theories with constant Ricci scalar in the Jordan/Einstein
frame can be described by Einstein or Einstein-Maxwell gravity with a cosmological term …

As our understanding of the past in a bouncing universe is limited, it becomes difficult to
propose a cosmological model which can give some understanding of the causal structure …