550 citations · 1.2k across the 23 of their papers we have counts for
25 papers
Cosmic topology. Part Va. Information content of the observable Universe
Deyan P. Mihaylov, Mikel Martin Barandiaran, Stefano Anselmi +14
If the Universe possesses a compact spatial topology with characteristic scale not much larger than the diameter of the observable Universe, then the associated symmetry transforma…
Search for Planetary-mass Black Holes with an Improved Viterbi Algorithm
Raul Rodriguez, George Alestas, Sachiko Kuroyanagi +1
Primordial black holes in the planetary-mass range have attracted renewed interest; however, the search for gravitational waves from such binaries remains challenging due to their…
The Topology of the Universe
Craig J. Copi, Deyan P. Mihaylov, Anna Negro +14
Is the Universe infinite in all directions? The only way to know is to look. A non-trivial cosmic topology would imprint subtle signatures on the cosmic microwave background (CMB)…
DESI and Gravitational Wave Constraints Challenge Quintessential α-Attractor Inflation
Changcheng Jing, George Alestas, Sachiko Kuroyanagi
Quintessential inflation models provide a framework that simultaneously describes inflation and dynamical dark energy, the latter of which has recently received growing support fro…
Quantum Signatures of Cosmic Topology: How Casimir Backreaction Transmits Isotropy Violation
Anna Negro, Kurt Hinterbichler, Glenn D. Starkman +17
A finite, scheme-independent Casimir contribution to the stress-energy tensor arises naturally for quantum fields in universes with non-trivial spatial topology. We compute this Ca…
Cosmic topology. Part IIc. Detectability with non-standard primordial power spectrum
Joline Noltmann, Andrius Tamosiunas, Deyan P. Mihaylov +13
Non-trivial spatial topology of the Universe can imprint potentially observable signatures on the cosmic microwave background (CMB). In this study, we investigate how deviations fr…
DESI constraints on two-field quintessence with exponential potentials
George Alestas, Marienza Caldarola, Indira Ocampo +2
We investigate a quintessence model involving two scalar fields with double-exponential potentials. This configuration allows the system as a whole to emulate the dynamics of a sin…
Euclid: Forecasts on CDM consistency tests with growth rate data
I. Ocampo, D. Sapone, S. Nesseris +156
The large-scale structure (LSS) of the Universe is an important probe for deviations from the canonical cosmological constant and cold dark matter (CDM) model. A statistical…
Euclid preparation: Expected constraints on initial conditions
Euclid Collaboration, F. Finelli, Y. Akrami +307
The Euclid mission of the European Space Agency will deliver galaxy and cosmic shear surveys, which will be used to constrain initial conditions and statistics of primordial fluctu…
Has DESI detected exponential quintessence?
Yashar Akrami, George Alestas, Savvas Nesseris
The new Dark Energy Spectroscopic Instrument (DESI) DR2 results have strengthened the possibility that dark energy is dynamical, i.e., it has evolved over the history of the Univer…
DESI constraints on -attractor inflationary models
George Alestas, Marienza Caldarola, Sachiko Kuroyanagi +1
The recent results on the baryon acoustic oscillations measurements from the DESI collaboration have shown tantalizing hints for a time-evolving dark energy equation of state param…
To curve, or not to curve: Is curvature-assisted quintessence observationally viable?
George Alestas, Matilda Delgado, Ignacio Ruiz +3
Single-field models of accelerated expansion with nearly flat potentials, despite being able to provide observationally viable explanations for the early-time cosmic inflation and…
Enhancing Cosmological Model Selection with Interpretable Machine Learning
Indira Ocampo, George Alestas, Savvas Nesseris +1
We propose a novel approach using neural networks (NNs) to differentiate between cosmological models, and implemented LIME as an interpretability approach to identify the key featu…
Euclid. I. Overview of the Euclid mission
Euclid Collaboration, Y. Mellier, Abdurro'uf +1134
The current standard model of cosmology successfully describes a variety of measurements, but the nature of its main ingredients, dark matter and dark energy, remains unknown. Eucl…
Applying the Viterbi Algorithm to Planetary-Mass Black Hole Searches
George Alestas, Gonzalo Morras, Takahiro S. Yamamoto +3
The search for subsolar mass primordial black holes (PBHs) poses a challenging problem due to the low signal-to-noise ratio, extended signal duration, and computational cost demand…
Machine learning constraints on deviations from general relativity from the large scale structure of the Universe
George Alestas, Lavrentios Kazantzidis, Savvas Nesseris
We use a particular machine learning approach, called the genetic algorithms (GA), in order to place constraints on deviations from general relativity (GR) via a possible evolution…
Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies
Elcio Abdalla, Guillermo Franco Abellán, Amin Aboubrahim +200
In this paper we will list a few important goals that need to be addressed in the next decade, also taking into account the current discordances between the different cosmological…
Constraining a late time transition of using low-z galaxy survey data
G. Alestas, L. Perivolaropoulos, K. Tanidis
It has recently been pointed out that a gravitational transition taking place at a recent redshift , reducing the effective gravitational constant by about $10\%…
Late-transition vs smooth deformation models for the resolution of the Hubble crisis
George Alestas, David Camarena, Eleonora Di Valentino +4
Gravitational transitions at low redshifts () have been recently proposed as a solution to the Hubble and growth tensions. Such transitions would naturally lead to a trans…
Late time approaches to the Hubble tension deforming , worsen the growth tension
G. Alestas, L. Perivolaropoulos
Many late time approaches for the solution of the Hubble tension use late time smooth deformations of the Hubble expansion rate of the Planck18/CDM best fit to match the…
Hints for a gravitational constant transition in Tully-Fisher data
George Alestas, Ioannis Antoniou, Leandros Perivolaropoulos
We use an up to date compilation of Tully-Fisher data to search for transitions in the evolution of the Tully-Fisher relation. Using an up to date data compilation, we find hints a…
A phantom transition at as a resolution of the Hubble tension
George Alestas, Lavrentios Kazantzidis, Leandros Perivolaropoulos
A rapid phantom transition of the dark energy equation of state parameter at a transition redshift of the form with can lead to a higher…
Existence and Stability of Static Spherical Fluid Shells in a Schwarzschild-Rindler-anti-de Sitter Metric
G. Alestas, G. V. Kraniotis, L. Perivolaropoulos
We demonstrate the existence of static stable spherical fluid shells in the Schwarzschild-Rindler-anti-de Sitter (SRAdS) spacetime where $ds^2 = f(r)dt^{2} -\frac{dr^{2}}{f(r)}-r^{…
Tension, Phantom Dark Energy and Cosmological Parameter Degeneracies
G. Alestas, L. Kazantzidis, L. Perivolaropoulos
Phantom dark energy can produce amplified cosmic acceleration at late times, thus increasing the value of favored by CMB data and releasing the tension with local measurement…