31 citations · 55 across the 9 of their papers we have counts for
9 papers
The friction-era VOS amplitude of a string network from nematic disclination data
Dimitrios Efstratiou, Evangelos Achilleas Paraskevas, Leandros Perivolaropoulos
A tangle of line defects coarsens as the mean spacing between neighbouring lines grows. In a viscous medium the motion is overdamped, and the velocity-dependent one-scale (VOS)…
Static Dark Fluid Thin Shells in Schwarzschild-de Sitter Spacetimes: Stability and Black Hole Shadows
Dimitrios Efstratiou, Evangelos Achilleas Paraskevas, Leandros Perivolaropoulos
We study the existence and radial stability of static, spherically symmetric thin shells joining two Schwarzschild-de Sitter (SdS) spacetimes . Near the equilibrium…
Addressing the DESI DR2 Phantom-Crossing Anomaly and Enhanced Tension with Reconstructed Scalar-Tensor Gravity
Dimitrios Efstratiou, Evangelos Achilleas Paraskevas, Leandros Perivolaropoulos
Recent cosmological data, including DESI DR2, highlight significant tensions within the CDM paradigm. When analyzed in the context of General Relativity (GR), the latest DESI da…
Probing the Universe's Topology through a Quantum System?
Evangelos Achilleas Paraskevas, Leandros Perivolaropoulos
The global topology of the Universe could, in principle, affect quantum systems through boundary condition constraints. We investigate this connection by analyzing how compact, fla…
Gravitational Wave Signatures Induced by Dark Fluid Accretion in Binary Systems
Evangelos Achilleas Paraskevas, Leandros Perivolaropoulos
We investigate the impact of dark fluid accretion on gravitational waveforms emitted by a compact binary system consisting of a supermassive black hole and a stellar-mass black hol…
Linear matter density perturbations in the CDM model: Examining growth dynamics and addressing the tension
Özgür Akarsu, Arman Çam, Evangelos A. Paraskevas +1
We investigate linear matter density perturbations in the CDM, in which the is replaced by late-time () mirror AdS-dS transition, resulting in distinct growt…
Transition dynamics in the CDM model: Implications for bound cosmic structures
Evangelos A. Paraskevas, Arman Cam, Leandros Perivolaropoulos +1
We explore the predictions of CDM, a novel framework suggesting a rapid anti-de Sitter (AdS) to de Sitter (dS) vacua transition in the late Universe, on bound cosmic str…
The density of virialized clusters as a probe of dark energy
Evangelos A. Paraskevas, Leandros Perivolaropoulos
We use the spherical collapse model to demonstrate that the observable average density of virialized clusters depends on the properties of dark energy along with the properties of…
Effects of a Late Gravitational Transition on Gravitational Waves and Anticipated Constraints
Evangelos Achilleas Paraskevas, Leandros Perivolaropoulos
We investigate the evolution of gravitational waves through discontinuous evolution (transition) of the Hubble expansion rate at a sudden cosmological singularity, which may…