8 papers
A unified scalar-field resolution of the , and evolving Dark Energy tensions
Gerasimos Kouniatalis
We propose a unified scalar-field framework that addresses, within standard general relativity, three current cosmological anomalies: the tension, the mild preference for red…
A null test of the Hubble tension
Gerasimos Kouniatalis, Emmanuel N. Saridakis
The origin of the Hubble tension remains one of the central open problems in modern cosmology, with competing explanations invoking either early-Universe physics, late-time modific…
Bohmian Quantum Cosmology from the Wheeler-DeWitt Equation
Spyros Basilakos, Gerasimos Kouniatalis, Emmanuel N. Saridakis +1
We construct a Bohmian quantum cosmological model for a spatially flat Friedmann Robertson Walker universe filled with a single scalar field whose potential provides a unified desc…
Near-horizon Geodesic Instabilities and Anomalous Decay of Quasinormal Modes in Weyl Black Holes
Gerasimos Kouniatalis, P. A. González, Eleftherios Papantonopoulos +1
We study the stability of the Weyl geometry considering an exact black hole solution. By calculating the geodesics of massless and massive scalar fields orbiting outside the Weyl b…
Lensing by black holes within astrophysical environments
Gerasimos Kouniatalis, Arthur G. Suvorov, Kyriakos Destounis
Astrophysical black holes are likely to be surrounded by various forms of matter in the form of disks or halos. While a number of studies have examined the impact of an environment…
Inflation from a generalized exponential plateau: towards extra suppressed tensor-to-scalar ratios
Gerasimos Kouniatalis, Emmanuel N. Saridakis
We investigate a standard minimally-coupled scalar-field inflationary scenario, which is based on a new potential, with suitably generalized plateau features, that leads to extra s…