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It has been recently shown that cosmological models with scale-dependent primordial non-Gaussianities (sPNG) could provide a possible path to solve current cosmic tensions. Moreover, it has been pointed out that some of these models might…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-08 Clément Stahl , Benoit Famaey , Rodrigo Ibata , Katarina Kraljic , Fabien Castillo

An interaction between dark matter and dark energy, proportional to the product of their energy densities, results in a scaling behavior of the ratio of these densities with respect to the scale factor of the Robertson-Walker metric. This…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-01 R. F. vom Marttens , L. Casarini , W. S. Hipólito-Ricaldi , W. Zimdahl

We study second-order cosmological perturbations in scalar-tensor models of dark energy that satisfy local gravity constraints, including f(R) gravity. We derive equations for matter fluctuations under a sub-horizon approximation and…

Astrophysics · Physics 2010-10-12 Takayuki Tatekawa , Shinji Tsujikawa

The current cosmological model, known as the $\Lambda$-Cold Dark Matter model (or $\Lambda$CDM for short) is one of the most astonishing accomplishments of contemporary theoretical physics. It is a well-defined mathematical model which…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-25 Pedro G. Ferreira , Alexander Roskill

Exotic dark matter (EDM) refers to a dark matter species whose equation of state deviates from zero at late times. This behavior enables it to model a variety of non-standard late-time cosmologies, offering alternatives to various dark…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-24 Matteo Braglia , Xingang Chen , Abraham Loeb

The current standard model of cosmology - the {\ensuremath{\Lambda}}CDM model - is appropriately named after its controversial foreign ingredients: a cosmological constant ({\ensuremath{\Lambda}}) that accounts for the recent accelerated…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-26 Elsa M. Teixeira

The canonical cosmological constant dominated cold dark matter model (LCDM) may possess too much power on small scales at z=0, manifested as central over-concentration of dark matter and over-abundance of dwarf galaxies. We suggest an…

Astrophysics · Physics 2009-10-31 Renyue Cen

Could Machine Learning (ML) make fundamental discoveries and tackle unsolved problems in Cosmology? Detailed observations of the present contents of the universe are consistent with the Cosmological Constant Lambda and Cold Dark Matter…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-10 Ofer Lahav

Interacting dark energy-dark matter models have been widely analyzed in the literature in an attempt to find traces of new physics beyond the usual cosmological ($\Lambda$CDM) models. Such a coupling between both dark components is usually…

General Relativity and Quantum Cosmology · Physics 2022-08-17 Diego Álvarez-Ortega , Gonzalo J. Olmo , Diego Rubiera-García , Diego Sáez-Chillón Gómez

Recent measurements of the parameters of the Concordance Cosmology Model ($\Lambda$CDM) done in the low-redshift Universe with Supernovae Ia/Cepheids, and in the distant Universe done with Cosmic Microwave Background (CMB) imply different…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 B. Czerny , M. L. Martínez-Aldama , G. Wojtkowska , M. Zajaček , P. Marziani , D. Dultzin , M. H. Naddaf , S. Panda , R. Prince , R. Przyluski , M. Ralowski , M. Śniegowska

The recent robust and homogeneous analysis of the world's supernova distance-redshift data, together with cosmic microwave background and baryon acoustic oscillation data, provides a powerful tool for constraining cosmological models. Here…

The nature of dark matter is increasingly constrained by cosmological data. In this paper, we examine the implications of the Cosmic Microwave Background anisotropy limits on the density of cold dark matter under different theoretical…

Astrophysics · Physics 2009-11-07 A. Melchiorri , J. Silk

Early dark energy (EDE) models are a class of quintessence dark energy with a dynamically evolving scalar field which display a small but non-negligible amount of dark energy at the epoch of matter-radiation equality. Compared with a…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-02 Difu Shi , Carlton M. Baugh

The dark energy plus cold dark matter ($\Lambda$CDM) cosmological model has been a demonstrably successful framework for predicting and explaining the large-scale structure of Universe and its evolution with time. Yet on length scales…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-04 James S. Bullock , Michael Boylan-Kolchin

We perform a detailed comparison between the Logotropic model [P.H. Chavanis, Eur. Phys. J. Plus 130 (2015) 130] and the $\Lambda$CDM model. These two models behave similarly at large (cosmological) scales up to the present. Differences…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-17 Pierre-Henri Chavanis , Suresh Kumar

The $\Lambda$CDM model, or concordance cosmology, as it is often called, is a paradigm at its maturity. It is clearly able to describe the universe at large scale, even if some issues remain open, such as the cosmological constant problem ,…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-27 Antonino Del Popolo , Morgan Le Delliou

We present a convolutional neural network to classify distinct cosmological scenarios based on the statistically similar weak-lensing maps they generate. Modified gravity (MG) models that include massive neutrinos can mimic the standard…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-17 Austin Peel , Florian Lalande , Jean-Luc Starck , Valeria Pettorino , Julian Merten , Carlo Giocoli , Massimo Meneghetti , Marco Baldi

We apply several statistical estimators to high-resolution N-body simulations of two currently viable cosmological models: a mixed dark matter model, having $\Omega_\nu=0.2$ contributed by two massive neutrinos (C+2\nuDM), and a Cold Dark…

Astrophysics · Physics 2009-10-28 S. Ghigna , S. Borgani , M. Tucci , S. A. Bonometto , A. Klypin , J. P. Primack

Quartessence is one of the alternatives to Lambda-CDM that has lately attracted considerable interest. According to this unifying dark matter/energy scenario, the Universe evolved from an early non-relativistic matter-dominated phase to a…

Astrophysics · Physics 2009-11-10 R. R. R. Reis , M. Makler , I. Waga

The simplest cosmological model ($\Lambda$CDM) is well-known to suffer from the Hubble tension, namely an almost $5 \sigma$ discrepancy between the (model-based) early-time determination of the Hubble constant $H_0$ and its late-time (and…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-06 Darshan Kumar , Debajyoti Choudhury , Debottam Nandi
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