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Related papers: Milgrom's Law and Lambda's Shadow: How Massive Gra…

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In the $\Lambda$CDM model, dark energy is viewed as a constant vacuum energy density, the cosmological constant in the Einstein--Hilbert action. This assumption can be relaxed in various models that introduce a dynamical dark energy. In…

High Energy Physics - Theory · Physics 2020-11-19 Vishnu Jejjala , Michael J. Kavic , Djordje Minic , Tatsu Takeuchi

We consider spatially homogeneous and isotropic Friedmann-Robertson-Walker (FRW) solutions of Milgrom's recently proposed class of bimetric theories of gravity. These theories have two different regimes, corresponding to high and low…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Timothy Clifton , Thomas G. Zlosnik

To describe dark energy we introduce a fluid model with no free parameter on the microscopic level. The constituents of this fluid are massless particles which are a dynamical realisation of the unextended $D=(3+1)$ Galilei algebra. These…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-29 P. C. Stichel , W. J. Zakrzewski

The stability of galaxies is either explained by the existence of dark matter or caused by a modification of Newtonian acceleration (MOND). Here we show that the modification of the Newtonian dynamics can equally well be obtained by a…

Astrophysics of Galaxies · Physics 2024-04-24 Søren Toxvaerd

Modified Newtonian dynamics by Milgrom is a paradigm for explaining the rotation curves of spiral galaxies and various other large scale structures. This paradigm includes several different theories. Here we present Milgrom's modified…

General Relativity and Quantum Cosmology · Physics 2021-11-12 Ahmad Shariati , Nosratollah Jafari

The idea that the vacuum energy density $\rho_{\Lambda}$ could be time dependent is a most reasonable one in the expanding Universe; in fact, much more reasonable than just a rigid cosmological constant for the entire cosmic history. Being…

General Relativity and Quantum Cosmology · Physics 2015-07-08 Harald Fritzsch , Joan Sola

The cosmological constant problem is one of the greatest challenges in contemporary physics, since it is deeply rooted in the problematic interplay between quantum fields and gravity. The aim of this work is to review the key conceptual…

General Relativity and Quantum Cosmology · Physics 2025-04-23 Federico Scali

This work verifies the principle that gravitation is caused by {\it energy} and not simply by mass alone. A model is proposed in which cosmic ray protons flow radially through the galaxy. The resulting electric field energy creates a…

General Physics · Physics 2014-07-29 Kenneth Dalton

Verlinde suggested a new theory of gravity called ``emergent gravity,'' which resembles Modified Newtonian Dynamics, the alternative to dark matter theory. For his version of Milgrom's constant, he theoretically derived…

General Physics · Physics 2025-08-21 Youngsub Yoon , Ho Seong Hwang

In our recently proposed quantum theory of gravity, the universe is made of `atoms' of space-time-matter (STM). Planck scale foam is composed of STM atoms with Planck length as their associated Compton wave-length. The quantum dispersion…

General Relativity and Quantum Cosmology · Physics 2020-08-03 Tejinder P. Singh

A great number of macroquantum laws connecting gravity and electromagnetism if found empirically. To describe them the model of anisotropic gravitational field is proposed. This field is build as a superposition of planes and force lines…

General Physics · Physics 2007-05-23 Alexander M. Ilyanok

Context. The external regions of galaxy clusters may be under strong influence of the dark energy, discovered by observations of the SN Ia at redshift z < 1. Aims. The presence of the dark energy in the gravitational equilibrium equation,…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-05 Marco Merafina , Gennady S. Bisnovatyi-Kogan , Martina Donnari

We review current observations of the homogeneous cosmological expansion which, because they measure only kinematic variables, cannot determine the dynamics driving the recent accelerated expansion. The minimal fit to the data, the flat…

Astrophysics · Physics 2015-05-13 Sidney Bludman

The high-quality cosmological data, which became available in the last decade, have thrusted upon us a rather preposterous composition for the universe which poses one of the greatest challenges theoretical physics has ever faced: the…

Astrophysics · Physics 2015-06-24 J. S. Alcaniz

A special class of conformal gravity theories is proposed to solve the long standing problem of the fine-tuned cosmological constant. In the proposed model time evolution of the inflaton field leaves behind a nearly vanishing, but finite…

High Energy Physics - Phenomenology · Physics 2022-04-25 M. Yoshimura

It is shown that gravity can be incorporated into the Standard Model (SM) in a way solving the hierarchy problem. For this, the SM effective action in flat spacetime is adapted to curved spacetime via not only the general covariance but…

High Energy Physics - Phenomenology · Physics 2017-03-17 Durmus Demir

The last decade has shown a considerable development of gravitational lensing for cosmology because it probes the amount and the nature of dark matter, and provides information on the density parameter $\Omega$, the cosmological constant…

Astrophysics · Physics 2007-05-23 Y. Mellier , F. Bernardeau , L. van Waerbeke

Perhaps the deepest mystery of our accelerating Universe in expansion is the existence of a tiny and rigid cosmological constant, $\Lambda$. Its size is many orders of magnitude below the expected one in the standard model of particle…

General Relativity and Quantum Cosmology · Physics 2015-04-03 Joan Sola , Adria Gomez-Valent

The current cosmological paradigm sees the formation and evolution of the cosmic large-scale structure as governed by the gravitational attraction of the Dark Matter (DM) and the repulsion of the Dark Energy (DE). We characterize the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 P. Teerikorpi , P. Heinämäki , P. Nurmi , A. D. Chernin , M. Einasto , M. Valtonen , G. Byrd

It is argued that the discovery of cosmic acceleration could have been anticipated on thermodynamic grounds, namely, the generalized second law and the approach to equilibrium at large scale factor. Therefore, the existence of dark energy…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Ninfa Radicella , Diego Pavón