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Related papers: An Isocurvature Mechanism for Structure Formation

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In the standard cosmological model a mysterious cold dark matter (CDM) component dominates the formation of structures. Numerical studies of the formation of CDM halos have produced several robust results that allow unique tests of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Jürg Diemand , Ben Moore

The development of numerical N -body simulations have allowed to study formation process and evolution of galaxies at different scales. This paper presents the fundamental concepts of N-body systems applied to the cosmological evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-12 Jazhiel Chacon , J. Alberto Vazquez , Ruslan Gabbasov

A single fluid approximation which treats perturbations in baryons and dark matter as equal has sometimes been used to calculate the growth of linear matter density perturbations in the Universe. We demonstrate that properly accounting for…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Soma De , James B. Dent , Lawrence M. Krauss

We propose a novel mechanism for the formation of primordial black holes by demonstrating that the delayed production of isocurvature perturbations resulting from Poisson fluctuations within the domain wall network can lead to collapse and…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-07 Bo-Qiang Lu , Cheng-Wei Chiang , Tianjun Li

The cold dark matter model has become the leading theoretical paradigm for the formation of structure in the Universe. Together with the theory of cosmic inflation, this model makes a clear prediction for the initial conditions for…

We study the formation of structure in the Universe assuming that dark matter can be described by a scalar field $\tilde{\Phi}$ with a potential $V(\Phi)=-\mathfrak{m}^{2}\tilde{\Phi}^{2}/2+\lambda\tilde{\Phi}^4/4$. We derive the evolution…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-09 Juan Magaña , Tonatiuh Matos , Abril Suárez , F. J. Sánchez-Salcedo

We analyse how dark matter (DM) can be produced in the early universe, working in the framework of a hidden sector charged under a U(1)' gauge symmetry and interacting with the Standard Model through kinetic mixing. Depending on the masses…

High Energy Physics - Phenomenology · Physics 2019-11-27 Thomas Hambye , Michel H. G. Tytgat , Jérôme Vandecasteele , Laurent Vanderheyden

We consider decaying dark matter (DDM) as a resolution to the possible tension between cosmic microwave background (CMB) and weak lensing (WL) based determinations of the amplitude of matter fluctuations, $\sigma_8$. We perform N-body…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-05 Kari Enqvist , Seshadri Nadathur , Toyokazu Sekiguchi , Tomo Takahashi

In this talk, we present a mechanism of Dark Matter production during first order phase transitions and happening via the collision of the bubble wall and plasma quanta. We will first study the possibility that the dark matter is produced…

High Energy Physics - Phenomenology · Physics 2024-12-10 Miguel Vanvlasselaer

The suppression of cosmological structure at small scales is a key signature of dark matter (DM) produced via freeze-in in the low-mass regime. We present a comprehensive analysis of its impact, incorporating recent constraints from Milky…

High Energy Physics - Phenomenology · Physics 2025-12-12 Francesco D'Eramo , Alessandro Lenoci , Ariane Dekker

Quantum fluctuations created during inflation can account for the observed matter distribution in the linear regime if the universe has two components of dark matter, one which is cold and collisionless, and the other which is hot and free…

Astrophysics · Physics 2007-05-23 Richard A. Battye , Joao Magueijo , Jochen Weller

We present a mechanism for dark matter (DM) production involving a self-interacting sector that at early times is ultra-relativistic but far-underpopulated relative to thermal equilibrium (such initial conditions often arise, e.g., from…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-28 John March-Russell , Hannah Tillim , Stephen M. West

The existence of dark radiation that is completely decoupled from the standard model in the early Universe leaves open the possibility of an associated dark radiation isocurvature mode. We show that the presence of dark radiation…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-12 Peter Adshead , Gilbert Holder , Pranjal Ralegankar

We explore an interacting dark matter (IDM) model that allows for a fraction of dark matter (DM) to undergo velocity-independent scattering with baryons. In this scenario, structure on small scales is suppressed relative to the cold DM…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-21 Adam He , Mikhail M. Ivanov , Rui An , Vera Gluscevic

We propose a new mechanism for thermal dark matter freezeout, termed Co-Decaying Dark Matter. Multi-component dark sectors with degenerate particles and out-of-equilibrium decays can co-decay to obtain the observed relic density. The dark…

High Energy Physics - Phenomenology · Physics 2016-12-08 Jeff Asaf Dror , Eric Kuflik , Wee Hao Ng

Cosmological backreaction suggests a link between structure formation and the expansion history of the Universe. In order to quantitatively examine this connection, we dynamically investigate a volume partition of the Universe into over--…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-18 Alexander Wiegand , Thomas Buchert

Recent high-resolution simulations that include Cold Dark Matter (CDM) and baryons have shown that baryonic physics can dramatically alter the dark matter structure of galaxies. These results modify our predictions for observed galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-30 Alyson Brooks

We study the cosmological consequences of co-decaying dark matter - a recently proposed mechanism for depleting the density of dark matter through the decay of nearly degenerate particles. A generic prediction of this framework is an early…

High Energy Physics - Phenomenology · Physics 2018-03-28 Jeff A. Dror , Eric Kuflik , Brandon Melcher , Scott Watson

We analyse the formation of cosmic structures in models where the dark matter is dominated by light gravitinos with mass of $ 100$ eV -- 1 keV, as predicted by gauge-mediated supersymmetry (SUSY) breaking models. After evaluating the number…

Astrophysics · Physics 2016-08-15 Elena Pierpaoli , Stefano Borgani , Antonio Masiero , Masahiro Yamaguchi

In this manuscript, we investigate late-time cosmology and the evolution of cosmic structures using an interacting dark fluid model in which dark matter (DM) and dark energy (DE) interact through a diffusive mechanism. To provide a…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-01 Shambel Sahlu , Upala Mukhopadhyay , Remudin R. Mekuria , Amare Abebe