242 citations · 1.2k across the 14 of their papers we have counts for
11 papers · 1 filter
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…
Observational constraints on the deceleration parameter in a tilted universe
Kerkyra Asvesta, Lavrentios Kazantzidis, Leandros Perivolaropoulos +1
We study a parametrization of the deceleration parameter in a tilted universe, namely a cosmological model equipped with two families of observers. The first family follows the smo…
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…
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…
Hints for possible low redshift oscillation around the best fit CDM model in the expansion history of the Universe
L. Kazantzidis, H. Koo, S. Nesseris +2
We search for possible deviations from the expectations of the concordance CDM model in the expansion history of the Universe by analysing the Pantheon Type Ia Supernovae (SnIa)…
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…
Hints of a Local Matter Underdensity or Modified Gravity in the Low Pantheon data
L. Kazantzidis, L. Perivolaropoulos
A redshift tomography of the Pantheon type Ia supernovae (SnIa) data focusing on the best fit value of the absolute magnitude and/or Hubble constant in the context of …
Is gravity getting weaker at low z? Observational evidence and theoretical implications
Lavrentios Kazantzidis, Leandros Perivolaropoulos
Dynamical observational probes of the growth of density perturbations indicate that gravity may be getting weaker at low redshifts . This evidence is at about level and c…
Constraining power of cosmological observables: blind redshift spots and optimal ranges
L. Kazantzidis, L. Perivolaropoulos, F. Skara
A cosmological observable measured in a range of redshifts can be used as a probe of a set of cosmological parameters. Given the cosmological observable and the cosmological parame…
Evolution of the tension with the Planck15/CDM determination and implications for modified gravity theories
Lavrentios Kazantzidis, Leandros Perivolaropoulos
We construct an updated extended compilation of distinct (but possibly correlated) Redshift Space Distortion (RSD) data published between 2006 and 2018. It consists of 63…