Bounce cosmology in $$f({\mathcal {R}})$$ gravity

A Non-Polynomial Gravity Formulation for Loop Quantum Cosmology Bounce

Recently the so-called mimetic gravity approach has been used to obtain corrections to the Friedmann equation of General Relativity similar to the ones present in loop quantum cosmology. In this paper, we propose an alternative way to derive this modified Friedmann equation via the so-called non-polynomial gravity approach, which consists of adding geometric non-polynomial higher derivative ter...

Bounce Loop Quantum Cosmology Corrected Gauss-Bonnet Gravity

We develop an effective Gauss-Bonnet extension of Loop Quantum Cosmology, by introducing holonomy corrections in modified F (G) theories of gravity. Within the context of our formalism, we provide a perturbative expansion in the critical density, a parameter characteristic of Loop Quantum Gravity theories, and we result in having leading order corrections to the classical F (G) theories of grav...

Non - perturbative Gravity , Hagedorn Bounce & CMB

In [1] it was shown how non-perturbative corrections to gravity can resolve the big bang singularity, leading to a bouncing universe. Depending on the scale of the nonperturbative corrections, the temperature at the bounce may be close to or higher than the Hagedorn temperature. If matter is made up of strings, then massive string states will be excited near the bounce, and the bounce will occu...

Modified gravity and cosmology

Lorentzian Gravity and Cosmology

If a material vacuum exists, with the properties of a superfluid through which already recognized material moves, then it is capable of acting as a universal reference frame and as an intermediary for the production of particle pairs throughout the universe, which as they cool and recombine, become the source of both high-and low-temperature cosmic background radiation, as observed. Moreover, i...