19 papers
Adiabatic Perturbations in GW170817-Compatible Einstein-Gauss-Bonnet Inflation
S. D. Odintsov, V. K. Oikonomou
We study the adiabaticity of the cosmological perturbations in the context of inflationary Einstein-Gauss-Bonnet theories. We focus on viable inflationary Einstein-Gauss-Bonnet the…
ACT Data and Positive Running of the Spectral Index for Scalar Theory and Modified Gravity
S. D. Odintsov, V. K. Oikonomou
In this work we address the possibility of having a positive running of the spectral index in inflationary theories. The recent ACT data indicate mildly that the running of the spe…
Dark Energy in Ghost-free non-local Gravity
S. D. Odintsov, V. K. Oikonomou, G. S. Sharov
Ghost-free non-local gravity is investigated with regards to its late-time dynamics. Viable solutions in this model are confronted with the observational data including the Pantheo…
String-inspired Gauss-Bonnet Gravity Inflation and ACT
S. D. Odintsov, V. K. Oikonomou, Pyotr Tsyba +2
In this article we present a systematic observational verification of the ghost-free string-inspired model, where the Gauss-Bonnet invariant is non-minimally cou…
-corrected Tachyon Scalar Field Inflation, the ACT Data, and Phantom Transition
S. D. Odintsov, V. K. Oikonomou
Phantom divide line transitions are not possible in the context of single scalar field scalar-tensor theories. In this article we study a combined framework of a tachyonic minimall…
Ghost-free non-local Gravity Compatible with ACT
Shin'ichi Nojiri, S. D. Odintsov, V. K. Oikonomou
We confront the ghost-free non-local gravity theories with the latest Atacama Cosmology Telescope (ACT) constraints on the spectral index of the scalar perturbations and the…