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This paper is based on two insights: (1) that general relativity alone does not specify how much of the matter density contributes to the source term in Friedmann's equation, and how much contributes as the source of the gravitational…

General Relativity and Quantum Cosmology · Physics 2024-04-23 Richard J. Cook

A class of coordinate systems is found for Friedmann Cosmologies with local gravity such that it is possible to formulate quantum theory over astronomical and cosmological distances. When light from distance objects is treated as a quantum…

General Physics · Physics 2009-04-28 Charles Francis

We propose a new framework for studying the cosmology of $f(R)$ gravity which completely avoids using the reconstruction programme. This allows us to easily obtain a qualitative feel of how much the $\Lambda$CDM model differs from other…

General Relativity and Quantum Cosmology · Physics 2021-06-22 Saikat Chakraborty , Kelly MacDevette , Peter Dunsby

Many different techniques to analyze galaxy clustering data and obtain cosmological constraints have been proposed, tested and used. Given the large amount of data that will be available soon, it is worth investigating new observables and…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-23 Eleonora Vanzan , Alvise Raccanelli , Nicola Bartolo

The modern cosmology is based on inflationary models with baryosynthesis and dark matter/energy.It implies extension of particle symmetry beyond the Standard model. Studies of physical basis of the modern cosmology combine direct searches…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-08 M. Yu. Khlopov

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

The current expansion of the Universe has been observed to be accelerating, and the widely accepted spatially-flat concordance model of general relativistic cosmology attributes this phenomenon to a constant dark energy, a cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-13 Shulei Cao

Recent observations of high-redshift Type Ia supernovae have placed stringent constraints on the cosmological constant $\Lambda$. We explore the implications of these SNe observations for cosmological models in which a classically evolving…

Astrophysics · Physics 2009-10-30 Joshua A. Frieman , Ioav Waga

We present a new, cosmologically model-independent, statistical analysis of the Pantheon+ type Ia supernovae spectroscopic dataset, improving a standard methodology adopted by Lane et al. We use the Tripp equation for supernova…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-20 Antonia Seifert , Zachary G. Lane , Marco Galoppo , Ryan Ridden-Harper , David L. Wiltshire

Cosmological observables are used to construct cosmological models. Since cosmological observations are limited to the light cone, a fixed number of observables (even measured to arbitrary accuracy) may not uniquely determine a cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-20 Edward W. Kolb , Callum R. Lamb

We reconstruct an $f(R)$ gravity model that gives rise to the particular $\Lambda$CDM background evolution of the universe. We find well-defined, real-valued analytical forms for the $f(R)$ model to describe the universe both in the early…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Jian-hua He , Bin Wang

The extragalactic gamma-ray and neutrino emission may have a contribution from dark matter (DM) annihilations. In the case of discrepancies between observations and standard predictions, one could infer the DM pair annihilation cross…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-07 Ángeles Moliné , Jascha A. Schewtschenko , Sergio Palomares-Ruiz , Celine Boehm , Carlton M. Baugh

We replace general relativity (GR) and the cosmological constant ($\Lambda$) in the standard cosmology (SM-GR-$\Lambda$-CDM) with a Lorentz gauge theory of gravity (LGT) and show that the standard model (SM) neutrinos can be the cold dark…

General Physics · Physics 2018-08-14 Ahmad Borzou

Astrophysical observations have put unprecedentedly tight constraints on cosmological theories. The $\Lambda$CDM model, mathematically simple and fits observational data-sets well, is preferred for explaining the behavior of universe. But…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Qiang Zhang , Guang Yang , Qixiang Zou , Xinhe Meng , Keji Shen

The $\Lambda$CDM cosmology passes demanding tests that establish it as a good approximation to reality, but it could be improved. I present a list of possibly interesting and less well explored things that might yield hints to a better…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-08 P. J. E. Peebles

We review the distance modulus in twelve different cosmologies: the $\Lambda$CDM model, the wCDM model, the Cardassian model, the flat case, the $\phi$CDM cosmology, the Einstein--De Sitter model, the modified Einstein--De Sitter model, the…

General Physics · Physics 2021-07-27 Lorenzo Zaninetti

Recently H(z) data obtained from differential ages of galaxies have been proposed as a new geometrical probe of dark energy. In this paper we use those data, combined with other background tests (CMB shift and SNIa data), to constrain a set…

Astrophysics · Physics 2009-11-13 Ruth Lazkoz , Elisabetta Majerotto

We investigate a simple braneworld model in which the universe contains only cold dark matter and a cosmological constant, but the effective dark energy is phantom-like because of extra-dimensional gravity effects. Modified gravity screens…

Astrophysics · Physics 2014-10-13 Ruth Lazkoz , Roy Maartens , Elisabetta Majerotto

The standard cosmological model is based on general relativity and includes dark matter and dark energy. An important prediction of this model is a fixed relationship between the gravitational potentials responsible for gravitational…

Astrophysics · Physics 2008-11-26 Pengjie Zhang , Michele Liguori , Rachel Bean , Scott Dodelson

The conventional $\Lambda$CDM cosmological model supplemented by the inflation concept describes the Universe very well. However, there are still a few concerns: new Planck data impose constraints on the shape of the inflaton potential,…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-03 Branislav Vlahovic , Maxim Eingorn , Cosmin Ilie
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