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The rotation curves of some star forming massive galaxies at redshift two decline over the radial range of a few times the effective radius, indicating a significant deficit of dark matter (DM) mass in the galaxy centre. The DM mass deficit…

Astrophysics of Galaxies · Physics 2022-06-15 Go Ogiya , Daisuke Nagai

In this article we extend the study performed in our previous article on the collapse of primordial objects. We here analyze the behavior of the physical parameters for clouds ranging from $10^7M_\odot$ to $10^{15}M_\odot$. We studied the…

Astrophysics · Physics 2009-10-30 S. R. Oliveira , O. D. Miranda , J. C. N. de Araujo , R. Opher

In this paper, we re-evaluate the estimates of dust mass in galaxies and demonstrate that current dust models are incomplete and based on a priori assumptions. These models suffer from a circularity problem and account for only a small…

Astrophysics of Galaxies · Physics 2024-11-28 Václav Vavryčuk

Aims: The enigma of the missing baryons poses a prominent and unresolved problem in astronomy. Dispersion measures (DM) serve as a distinctive observable of fast radio bursts (FRBs). They quantify the electron column density along each line…

The observational relation between the density of baryon and dark matter in the Universe, $\Omega_{\rm DM}/\Omega_B\simeq 5$, is one of the most difficult problems to solve in modern cosmology. We discuss a scenario that explains this…

High Energy Physics - Phenomenology · Physics 2013-05-30 Kohei Kamada , Masahide Yamaguchi

The growth and virialization of spherical top-hat fluctuations, in coupled Dark Energy models, causes segregation between Dark Matter (DM) and baryons, as the gravitational infall into the potential well proceeds more slowly for the baryons…

Astrophysics · Physics 2009-11-13 Roberto Mainini

We examine the fully relativistic evolution of cosmic voids constituted by baryons and cold dark matter (CDM), represented by two non-comoving dust sources in a $\Lambda$CDM background. For this purpose, we consider numerical solutions of…

General Relativity and Quantum Cosmology · Physics 2019-02-12 Ismael Delgado Gaspar , Juan Carlos Hidalgo , Roberto A. Sussman

The angular power spectrum and polarization of the cosmic microwave background radiation (CMB), the relative abundances of primordial hydrogen, deuterium and helium isotopes, and the large-scale structure of the universe all indicate that…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-02 Ehud Behar , Shlomo Dado , Arnon Dar , Ari Laor

The conventional cold, particle interpretation of dark matter (CDM) still lacks laboratory support and struggles with the basic properties of common dwarf galaxies, which have surprisingly uniform central masses and shallow density…

Astrophysics of Galaxies · Physics 2014-06-26 Hsi-Yu Schive , Tzihong Chiueh , Tom Broadhurst

Observations of spiral galaxies strongly support a one-to-one analytical relation between the inferred gravity of dark matter at any radius and the enclosed baryonic mass. It is baffling that baryons manage to settle the dark matter…

Astrophysics · Physics 2008-11-26 Benoit Famaey , Gianfranco Gentile , Jean-Philippe Bruneton , HongSheng Zhao

It is shown that the cosmological constant links the roots both of General Relativity and Newtonian gravity via the general function satisfying Newton's theorem according to which the gravitating sphere acts as a point mass situated in its…

General Relativity and Quantum Cosmology · Physics 2019-01-10 V. G. Gurzadyan

In the standard cosmological model, the Universe consists mainly of two invisible substances: vacuum energy with constant mass-density rho_v=\Lambda/(8pi G) (where Lambda is a `cosmological constant' originally proposed by Einstein and G is…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Matthew G. Walker , Abraham Loeb

There are many indications that ordinary matter represents only a tiny fraction of the matter content of the Universe, with the remainder assumed to consist of some different type of matter, which, for various reasons must be nonluminous…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Marcelo Salgado , Daniel Sudarsky , Hernando Quevedo

The dark energy, dark matter and baryon densities in the Universe are observed to be similar, with a factor of no more than 20 between the largest and smallest densities. We show that this coincidence can be understood via superhorizon…

High Energy Physics - Phenomenology · Physics 2015-06-12 John McDonald

Observations of galaxies suggest a one-to-one analytic relation between the inferred gravity of dark matter at any radius and the enclosed baryonic mass, a relation summarized by Milgrom's law of modified Newtonian dynamics (MOND). However,…

Astrophysics · Physics 2009-11-13 Jean-Philippe Bruneton , Stefano Liberati , Lorenzo Sindoni , Benoit Famaey

Cosmological perturbation theory provides the fundamental framework for describing the evolution of the matter-energy density field in an expanding Universe and serves as the basis for understanding the formation of large-scale structures…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-13 Diego Fernando Fonseca , Leonardo Castañeda , Luz Ángela García

We use cosmological hydrodynamical simulations of the APOSTLE project along with high-quality rotation curve observations to examine the fraction of baryons in {\Lambda}CDM haloes that collect into galaxies. This 'galaxy formation…

The rotation velocity profiles of galaxies (rotation curves) remain unexpectedly flat at large distances, where visible matter alone should make the rotation velocity decrease with radius. Conventionally, this requires a large amount of…

Astrophysics of Galaxies · Physics 2026-05-12 Kento Kamada

In recent years, unprecedented progress in observational cosmology has revealed a great deal of information about the formation and evolution of structures in the universe. This, in turn, has raised many challenging issues for the…

Astrophysics · Physics 2010-12-09 T. Roy Choudhury

We investigate the behaviour of cosmological baryons at low redshifts $z<5$ after reionization through analytic means. In particular, we study the density-temperature phase-diagram which describes the history of the gas. We show how the…

Astrophysics · Physics 2009-11-07 P. Valageas , R. Schaeffer , J. Silk