299 citations · 1.1k across the 42 of their papers we have counts for
10 papers · 1 filter
Sensitivity of calibration-free DESI DR2 BAO--supernova constraints to a distance-duality tilt
Stéphane Fay, Mikel Artola, Leandros Perivolaropoulos
Recent measurements from DESI baryon acoustic oscillations (BAO) have reported a moderate preference for dynamical dark energy, challenging the CDM paradigm. Nonetheless, such a…
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)…
Cosmographic Reconstruction of the Quintessence Potential in Scalar-Tensor Gravity
G. Antonopoulos, L. Perivolaropoulos
We generalise the cosmographic reconstruction programme of Chakraborty, Dunsby & Scherrer to scalar-tensor gravity. Working in the Jordan frame with a general non-minimal coupling…
A Friendly Phantom: Late-time AdS-to-dS transition and cosmological tensions
Özgür Akarsu, Leandros Perivolaropoulos, A. Emrah Yükselci +1
We present Ph-CDM, a phantom-scalar realization within General Relativity of the sign-switching cosmological-constant idea, CDM, in which a phantom scalar evo…
On the origin of the BAOtr-DESI tension
Ioannis Pantos, Leandros Perivolaropoulos
The fiducial-independent angular/transverse BAO dataset, obtained from two-point angular correlation functions in thin redshift shells (hereafter BAOtr), systematically prefers sma…
Impact of the SNe Ia Magnitude Transition at 20 Mpc on Cosmological Parameter Estimation
Leandros Perivolaropoulos, Chrisostomos-Panagiotis Stamou
We investigate the impact of a late-time transition in the standardized absolute magnitude on the best-fit values of cosmological parameters using the Pantheon+ dataset. Extend…
Testing gravitational wave polarizations with LISA
Shingo Akama, Maxence Corman, Paola C. M. Delgado +16
In this paper we quantify the ability of the Laser Interferometer Space Antenna (LISA) to test the presence of non-tensorial polarizations as well as modifications to the tensor on…
Status of the Tension: A 2026 Review of Probe Discrepancies
Ioannis Pantos, Leandros Perivolaropoulos
The parameter quantifies the amplitude of matter density fluctuations. A persistent discrepancy exists between early-universe CMB observations and…
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…
Dissecting the Hubble tension: Insights from a diverse set of Sound Horizon-free H0 measurements
Ioannis Pantos, Leandros Perivolaropoulos
The Hubble tension is commonly framed as a discrepancy between local, late-time measurements favoring km s Mpc and early-time, Sound-Horizon-based me…