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We present robust, model-marginalized limits on both the total neutrino mass ($\sum m_\nu$) and abundance ($N_{\rm eff}$) to minimize the role of parameterizations, priors and models when extracting neutrino properties from cosmology. The…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-14 Eleonora di Valentino , Stefano Gariazzo , Olga Mena

To explore the properties of space and initial singularities in the context of general relativity, where spacetime becomes poorly defined and no longer belongs to a regular manifold, we examine the evolution of the expansion of timelike…

General Relativity and Quantum Cosmology · Physics 2025-04-04 Abdel Nasser Tawfik , Azzah A. Alshehri , Antonio Pasqua

Models that involve extra dimensions have introduced completely new ways of looking up on old problems in theoretical physics. The aim of the present notes is to provide a brief introduction to the many uses that extra dimensions have found…

High Energy Physics - Phenomenology · Physics 2009-11-11 Abdel Pérez-Lorenzana

In the very last years, cosmological models where the properties of the dark components of the Universe - dark matter and dark energy - are accounted for by a single "dark fluid" have drawn increasing attention and interest. Amongst many…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-02 Stefano Camera , Carmelita Carbone , Lauro Moscardini

In order to quantitatively test the ability of averaged inhomogeneous cosmologies to correctly describe observations of the large scale properties of the Universe, we introduce a smoothed template metric corresponding to a constant spatial…

This article presents a novel mathematical formalism for advanced manifold--metric pairs, enhancing the frameworks of geometry and topology. We construct various D-dimensional manifolds and their associated metric spaces using functional…

General Topology · Mathematics 2026-04-24 Pierros Ntelis

On the basis of a previously established scalar-tensor extension of the $\Lambda$CDM model we develop an effective fluid approach for the matter growth function. This extended $\Lambda$CDM (henceforth $e_{\Phi}\Lambda$CDM) cosmology takes…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-01 W. Zimdahl , H. E. S. Velten , W. C. Algoner

We study cosmographic expansions of the luminosity distance for a variety of Lemaitre-Tolman-Bondi models which we specify inspired by local large-scale structures of the universe. We consider cosmographic expansions valid for general…

General Relativity and Quantum Cosmology · Physics 2024-11-11 Asha B. Modan , S. M. Koksbang

The cosmological principle asserts that on sufficiently large scales the Universe is homogeneous and isotropic on spatial slices. To deviate from this principle requires a departure from the FLRW ansatz. In this paper we analyze the…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-23 Andrei Constantin , Thomas R. Harvey , Sebastian von Hausegger , Andre Lukas

A recently proposed technique allows one to constrain both the background and perturbation cosmological parameters through the distribution function of supernova Ia apparent magnitudes. Here we extend this technique to alternative…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-28 Luca Amendola , Tiago Castro , Valerio Marra , Miguel Quartin

On the largest scales, the universe appears to be almost homogeneous and isotropic, adhering to the cosmological principle. In contrast, on smaller scales inhomogeneities and anisotropy become increasingly prominent, reflecting the origin,…

General Relativity and Quantum Cosmology · Physics 2025-10-07 Robbert W. Scholtens , Marcello Seri , Holger Waalkens , Rien van de Weygaert

Strong gravitational lens system catalogues are typically used to constrain a combination of cosmological and empirical power-law lens mass model parameters, often introducing additional empirical parameters and constraints from high…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-24 Christopher Harvey-Hawes , David L. Wiltshire

This is the fourth of a series of papers in which we derive simultaneous constraints on cosmological parameters and X-ray scaling relations using observations of the growth of massive, X-ray flux-selected galaxy clusters. Here we examine…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Adam Mantz , Steven W. Allen , David Rapetti

Strong gravitational lensing time-delay measurements, together with the distance sum rule (DSR), offer a model-independent approach to probe the geometry and expansion of the universe without relying on a fiducial cosmological model. In…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-04 Darshan Kumar , Deepak Jain , Shobhit Mahajan

We test and compare coasting cosmological models with curvature parameters ${k=\left\{ -1,0,+1 \right\}}$ in ${H_0^2 c^{-2}}$ units and the flat $\Lambda$CDM model by fitting them to cosmic chronometers (CC), the Pantheon+ sample of type Ia…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 Peter Raffai , Adrienn Pataki , Rebeka L. Böttger , Alexandra Karsai , Gergely Dálya

We have recently proposed a simple relativistic theory which reduces to modified Newtonian dynamics for the weak-field quasistatic situations applied to galaxies, and to cosmological behavior as in the $\Lambda$CDM model, yielding a…

General Relativity and Quantum Cosmology · Physics 2022-11-29 Constantinos Skordis , Tom Zlosnik

We review a set of the possible ways to constrain extended gravity models at Galaxy clusters scales (the regime of dark energy explanations and comparison with $\Lambda CDM$), for black hole shadows, gravitational wave astronomy, binary…

General Relativity and Quantum Cosmology · Physics 2022-05-17 Stanislav Alexeyev , Vyacheslav Prokopov

Expanding Thurston maps were introduced by M. Bonk and D. Meyer with motivation from complex dynamics and Cannon's conjecture from geometric group theory via Sullivan's dictionary. In this paper, we introduce subsystems of expanding…

Dynamical Systems · Mathematics 2024-12-31 Zhiqiang Li , Xianghui Shi , Yiwei Zhang

In this work, we investigate the General Relativistic Entropic Acceleration (GREA) framework, in which late-time acceleration emerges from entropy production associated with the cosmological horizon, and compare its performance with the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-03 Irene Graziotti , Chiara De Leo , Matteo Martinelli

We propose and implement a novel, robust, and non-parametric test of statistical isotropy of the expansion of the universe, and apply it to around one thousand type Ia supernovae from the Pantheon sample. We calculate the angular clustering…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-24 John Soltis , Arya Farahi , Dragan Huterer , C. Michael Liberato
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