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Related papers: Entropy Analysis of Dark Matter Halo Structures

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The rotation curves of dark matter dominated dwarf galaxies are analysed. The observations show that dark matter halos represent a one-parameter family with self similar density profiles. The global halo parameters, like total mass and…

Astrophysics · Physics 2007-05-23 Andreas Burkert

In the realm of thermodynamics of apparent horizon, we construct a dark energy (DE) model from 4-parameter generalized entropy of apparent horizon in a spatially non-flat universe. In particular, considering a non-zero spatial curvature of…

General Relativity and Quantum Cosmology · Physics 2025-04-07 Sergei D. Odintsov , Simone D'Onofrio , Tanmoy Paul

The laws of mechanics of stationary black holes bear a close resemblance with the laws of thermodynamics. This is not only a mathematical analogy but also a physical one that helps us answer deep questions related to the thermodynamic…

General Relativity and Quantum Cosmology · Physics 2010-07-26 Diptarka Das

We examine the second law of thermodynamics in the context of horizon cosmology, in particular, whether the change of total entropy (i.e. the sum of the entropy for the apparent horizon and the entropy for the matter fields) proves to be…

General Relativity and Quantum Cosmology · Physics 2024-04-09 Sergei D. Odintsov , Tanmoy Paul , Soumitra SenGupta

Navarro, Frenk, and White have suggested that the density profiles of simulated dark matter halos have a ``universal'' shape so that a given halo can be characterized by a single free parameter which fixes its mass. In this paper, we…

Astrophysics · Physics 2009-10-30 Richard N. Henriksen , Lawrence M. Widrow

To derive black hole thermodynamics in any quantum theory of gravity, one must introduce constraints that ensure that a black hole is actually present. For a large class of black holes, the imposition of such ``horizon constraints'' allows…

General Relativity and Quantum Cosmology · Physics 2015-05-13 S. Carlip

We construct condensate states encoding the continuum spherically symmetric quantum geometry of an horizon in full quantum gravity, i.e. without any classical symmetry reduction, in the group field theory formalism. Tracing over the bulk…

General Relativity and Quantum Cosmology · Physics 2016-05-27 Daniele Oriti , Daniele Pranzetti , Lorenzo Sindoni

We present a framework for dark matter (DM) halo formation based on a kinetic theory of self-gravitating fermions together with a solid connection to thermodynamics. Based on maximum entropy arguments, this approach predicts a most likely…

Astrophysics of Galaxies · Physics 2026-01-09 A. Krut , C. R. Argüelles , P. -H. Chavanis

Statistical mechanics explains thermodynamics in terms of (quantum) mechanics by equating the entropy of a microstate of a closed system with the logarithm of the number of microstates in the macrostate to which it belongs, but the question…

High Energy Physics - Theory · Physics 2007-05-23 Bernard S. Kay

We discuss the entropy change due to fragmentation for black hole solutions in various dimensions. We find three different types of behavior. The entropy may decrease, increase or have a mixed behavior, characterized by the presence of a…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Mariano Cadoni

Dark matter (DM) haloes forming near the thermal cut-off scale of the density perturbations are unique, since they are the smallest objects and form through monolithic gravitational collapse, while larger haloes contrastingly have…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-06 Go Ogiya , Oliver Hahn

Thermodynamics on the horizon of a flat universe at late times is studied in holographic cosmological models that assume an associated entropy on the horizon. In such models, a $\Lambda(t)$ model similar to a time-varying $\Lambda(t)$…

General Relativity and Quantum Cosmology · Physics 2020-01-01 Nobuyoshi Komatsu

We study two types of entropic-force models in a homogeneous, isotropic, spatially flat, matter-dominated universe. The first type is a `$\Lambda(t)$ type' similar to $\Lambda(t)$CDM (varying-lambda cold dark matter) models in which both…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-11 Nobuyoshi Komatsu , Shigeo Kimura

Ambient dark matter (DM) around binary black holes can imprint characteristic signatures on gravitational waves emitted from their merger. The exact signature depends sensitively on the DM density profile around the black holes. We run very…

Astrophysics of Galaxies · Physics 2025-11-05 Shingo Hirano , Naoki Yoshida

We study the imprint of Dark Energy on the density profile of Dark Matter halos using a set of high-resolution large volume cosmological N-body simulations from the Dark Energy Universe Simulation Series (DEUSS). We first focus on the…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-03 Irène Balmès , Yann Rasera , Pier-Stefano Corasaniti , Jean-Michel Alimi

We propose the use of a gravitational uncertainty principle for gravitation. We define the corresponding gravitational Planck's constant and the gravitational quantum of mass. We define entropy in terms of the quantum of gravity with the…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Antonio Alfonso-Faus

In a recent paper, Salvador-Sol\'e et al. (2012) have derived the typical inner structure of dark matter haloes from that of peaks in the initial random Gaussian density field, determined by the power-spectrum of density perturbations…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-13 Eduard Salvador-Solé , Sinue Serra , Alberto Manrique Guillermo González-Casado

Black hole entropy is studied for an exactly solvable model of two-dimensional gravity\cite{rst1}, using recently developed Noether charge techniques\cite{wald1}. This latter approach is extended to accomodate the non-local form of the…

High Energy Physics - Theory · Physics 2010-11-01 Robert C. Myers

We study the effects of mass and force resolution on the density profiles of galaxy-size Cold Dark Matter (CDM) halos in a flat, low-density cosmological model with vacuum energy. We show thatalthough increasing the mass and force…

Astrophysics · Physics 2008-11-26 Anatoly Klypin , Andrey V. Kravtsov , James Bullock , Joel Primack

The energy density of the holographic dark energy is based on the area law of entropy, and thus any modification of the area law leads to a modified holographic energy density. Inspired by the entropy expression associated with the apparent…

General Relativity and Quantum Cosmology · Physics 2016-03-16 A. Sheykhi , M. H. Dehghani , S. Ghaffari