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The logotropic model [P.H. Chavanis, Eur. Phys. J. Plus {\bf 130}, 130 (2015)] may be an interesting alternative to the $\Lambda$CDM model. It is able to account for the present accelerating expansion of the universe while solving at the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-19 Pierre-Henri Chavanis

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

A unification of dark matter and dark energy in terms of a logotropic perfect dark fluid has recently been proposed, where deviations with respect to the standard $\Lambda {\rm CDM}$ model are dependent on a single parameter $B$. In this…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-24 V. M. C. Ferreira , P. P. Avelino

In a recent article, Kleidis and Spyrou (2015) proposed that both dark matter (DM) and dark energy (DE) can be treated as a single component, if accommodated in the context of a polytropic DM fluid with thermodynamical content. Depending…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-25 Kostas Kleidis , Nikolaos K. Spyrou

In a previous paper we have introduced a new cosmological model that we called the logotropic model. The logotropic model is able to account, without free parameter, for the constant surface density of the dark matter halos, for their…

General Relativity and Quantum Cosmology · Physics 2019-12-03 Pierre-Henri Chavanis

It is well known that a canonical scalar field is able to describe either dark matter or dark energy but not both. We demonstrate that a non-canonical scalar field can describe both dark matter and dark energy within a unified setting. We…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-12 Varun Sahni , Anjan A Sen

We propose a heuristic unification of dark matter and dark energy in terms of a single dark fluid with a logotropic equation of state $P=A\ln(\rho/\rho_P)$, where $\rho$ is the rest-mass density, $\rho_P$ is the Planck density, and $A$ is…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-27 Pierre-Henri Chavanis

We discuss the connection between logotropes and polytropes in astrophysics and cosmology. The logotropic equation of state $P=A\ln(\rho/\rho_P)$ may be seen as a degenerate form of the polytropic equation of state $P=K\rho^{\gamma}$ in the…

General Relativity and Quantum Cosmology · Physics 2026-03-24 Pierre-Henri Chavanis

We propose a new class of cosmological unified dark sector models called "{\em Generalized Logotropic Models}". They depend on a free parameter $n$. The original logotropic model [P.H. Chavanis, Eur. Phys. J. Plus {\bf 130}, 130 (2015)] is…

General Relativity and Quantum Cosmology · Physics 2022-02-17 Hachemi B. Benaoum , Pierre-Henri Chavanis , Hernando Quevedo

We check the dynamical and observational features of four typologies of logotropic dark energy models, leading to a \emph{thermodynamic cosmic speed up} fueled by a single fluid that unifies dark energy and dark matter. We first present two…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-03 Kuantay Boshkayev , Talgar Konysbayev , Orlando Luongo , Marco Muccino , Francesco Pace

We construct cosmological models based on a complex scalar field with a power-law potential $V=\frac{K}{\gamma-1}(\frac{m}{\hbar})^{2\gamma}|\varphi|^{2\gamma}$ associated with a polytropic equation of state $P=K\rho^{\gamma}$ (the…

General Relativity and Quantum Cosmology · Physics 2022-08-17 Pierre-Henri Chavanis

We have considered a spatially flat, homogeneous and isotropic FLRW Universe filled with a single fluid, known as logotropic dark fluid (LDF), whose pressure evolves through a logarithmic equation of state. We use the recent Pantheon SNIa…

General Relativity and Quantum Cosmology · Physics 2021-01-15 Abdulla Al Mamon , Subhajit Saha

Arguably our current cosmological paradigm, the so-called $\Lambda$CDM `concordance model', faces an existential crisis. This has largely been brought about by its reliance on the twin concepts of dark matter and dark energy, and the…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-01 Robin Booth

The standard $\Lambda$CDM model of cosmology is formulated as a simple modified gravity coupled to a single scalar field ("darkon") possessing a non-trivial hidden nonlinear Noether symmetry. The main ingredient in the construction is the…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-12 David Benisty , Eduardo I. Guendelman , Emil Nissimov , Svetlana Pacheva

We found general solutions of matter stress-energy (non-)conservation in scalar-tensor FLRW-type cosmological models by extending the logotropic formalism to the case of non-minimal coupling between the scalar field and new dark fluid…

General Relativity and Quantum Cosmology · Physics 2024-12-19 Andrzej Borowiec , Marcin Postolak

The scalar field endowed with a cosh scalar field potential, behaves exactly in the same way as cold dark matter (CDM) in the region where the scalar field oscillates around its minimum. Also, in the linear regime, the scalar field dark…

Astrophysics · Physics 2021-02-09 Argelia Bernal , Tonatiuh Matos , Dario Nunez

We here propose a new class of barotropic factor for matter, motivated by properties of isotropic deformations of crystalline solids. Our approach is dubbed Anton-Schmidt's equation of state and provides a non-vanishing, albeit small,…

General Relativity and Quantum Cosmology · Physics 2017-12-13 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

We look for cosmologies with a scalar field (dark energy without cosmological constant), which mimic the standard $\Lambda CDM$ cosmological model yielding exactly the same large-scale geometry described by the evolution of the Hubble…

Astrophysics · Physics 2015-05-13 V. I. Zhdanov , G. Ivashchenko

This study investigates the potential of a cosmological model termed $\Lambda w$DM, in which a cosmological constant play the role of dark energy and dark matter is barotropic and has a constant equation of state parameter ($w_{\rm dm}$),…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-02 Yan-Hong Yao , Jian-Qi Liu

An alternative to the postulate of dark energy required to explain the accelerated expansion of the universe is to adopt an inhomogeneous cosmological model to explain the supernovae data without dark energy. We adopt a void cosmology…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-02 J. W. Moffat
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