Finite-time cosmological singularities and the possible fate of the Universe

J de Haro, S Nojiri, SD Odintsov, VK Oikonomou, S Pan - Physics Reports, 2023 - Elsevier
Singularities in any physical theory are either remarkable indicators of the unknown
underlying fundamental theory, or indicate a change in the description of the physical reality …

Beyond Einstein's General Relativity: Hybrid metric-Palatini gravity and curvature-matter couplings

T Harko, FSN Lobo - International Journal of Modern Physics D, 2020 - World Scientific
Einstein's General Relativity (GR) is possibly one of the greatest intellectual achievements
ever conceived by the human mind. In fact, over the last century, GR has proven to be an …

A refined Einstein–Gauss–Bonnet inflationary theoretical framework

VK Oikonomou - Classical and Quantum Gravity, 2021 - iopscience.iop.org
We provide a refined and much more simplified Einstein–Gauss–Bonnet inflationary
theoretical framework, which is compatible with the GW170817 observational constraints on …

[HTML][HTML] Phase-space analysis of a novel cosmological model in f (Q) theory

H Shabani, A De, TH Loo - The European Physical Journal C, 2023 - Springer
The vanishing affine connections have been used solely while adopting the modified f (Q)
gravity theory to the cosmology. Consequently, researchers could not get beyond what is …

Dynamical systems perspective of cosmological finite-time singularities in gravity and interacting multifluid cosmology

SD Odintsov, VK Oikonomou - Physical Review D, 2018 - APS
In this work we shall investigate the occurrence of future cosmological finite-time
singularities in the dynamical system corresponding to two cosmological theories, namely …

[HTML][HTML] Cosmology in symmetric teleparallel gravity and its dynamical system

J Lu, X Zhao, G Chee - The European Physical Journal C, 2019 - Springer
We explore an extension of the symmetric teleparallel gravity denoted the f (Q) theory, by
considering a function of the nonmetricity invariant Q as the gravitational Lagrangian. Some …

Kinetic axion gravity inflation

VK Oikonomou - Physical Review D, 2022 - APS
In this work we investigate the quantitative effects of the misalignment kinetic axion on R 2
inflation. Due to the fact that the kinetic axion possesses a large kinetic energy that …

[HTML][HTML] Dynamical stability analysis of accelerating f(T) gravity models

LK Duchaniya, SV Lohakare, B Mishra… - The European Physical …, 2022 - Springer
In this paper, we have emphasized the stability analysis of the accelerating cosmological
models obtained in f (T) gravity theory. The behaviour of the models based on the evolution …

Dynamical system analysis of generalized energy-momentum-squared gravity

S Bahamonde, M Marciu, P Rudra - Physical Review D, 2019 - APS
In this work we have investigated the dynamics of a recent modification to the general theory
of relativity, the energy-momentum squared gravity model f (R, T 2), where R represents the …

[HTML][HTML] Holographic realization of constant roll inflation and dark energy: An unified scenario

S Nojiri, SD Odintsov, T Paul - Physics Letters B, 2023 - Elsevier
In the formalism of generalized holographic dark energy, the infrared cut-off L IR is
generalized to the form, L IR= L IR (L p, L˙ p, L¨ p,⋯, L f, L˙ f, L¨ f,⋯, a, H, H˙, H¨,⋯), where L p …