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Related papers: Unimodular Diffusion and Interacting Vacuum Cosmol…

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Discrete diffusion has become a leading framework for generative modeling in various applications including language, vision, and biology. Existing convergence theory, however, exhibits fundamental limitations. KL-based analyses diverge…

Machine Learning · Computer Science 2026-05-19 Kelvin Kan , Xingjian Li , Benjamin J. Zhang , Tuhin Sahai , Stanley Osher , Markos A. Katsoulakis

This paper presents a systematic and accurate treatment of the evolution of cosmological perturbations in self-interacting dark matter models, for particles which decoupled from the primordial plasma while relativistic. We provide a…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-17 Rafael Yunis , Carlos R. Argüelles , Claudia G. Scóccola , Diana López Nacir , Gastón Giordano

We show that an interaction between dark matter and dark energy generically results in an effective dark energy equation of state of w<-1. This arises because the interaction alters the redshift-dependence of the matter density. An observer…

Astrophysics · Physics 2010-03-26 Subinoy Das , Pier Stefano Corasaniti , Justin Khoury

We study the transport property of diffusion in a finite translationally invariant quantum subsystem described by a tight-binding Hamiltonian with a single energy band and interacting with its environment by a coupling in terms of…

Statistical Mechanics · Physics 2010-03-01 Massimiliano Esposito , Pierre Gaspard

The conventional $\Lambda$CDM cosmological model supplemented by the inflation concept describes the Universe very well. However, there are still a few concerns: new Planck data impose constraints on the shape of the inflaton potential,…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-03 Branislav Vlahovic , Maxim Eingorn , Cosmin Ilie

The present work deals with an interacting dark energy model in the framework of f(T) cosmology. A cosmologically viable form of f(T) is chosen (T is the torsion scalar in teleparallelism) in the background of flat homogeneous and isotropic…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Sujay Kr. Biswas , Subenoy Chakraborty

We explore an interacting dark matter (DM)-dark energy (DE) framework that naturally yields an effective dynamical DE equation of state crossing the phantom barrier at early times, as indicated by recent DESI data, while also accounting for…

High Energy Physics - Phenomenology · Physics 2026-01-07 Basabendu Barman , Sudhakantha Girmohanta

One of the important issues both in particle physics and cosmology relates to whether dark energy is a cosmological constant $\Lambda$, or is dynamical in nature such as quintessence. In this work, we discuss a model of quintessence…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-10 Amin Aboubrahim , Pran Nath

Cosmological models assuming the scale invariance of the macroscopic empty space show an accelerated expansion, without calling for some unknown particles. Several comparisons between models and observations (tests on distances, m-z…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-04 Andre Maeder

We take a phenomenological approach to study the cosmological evolution of decaying vacuum cosmology ($\Lambda(t)$CDM) based on a simple assumption about the form of the modified matter expansion rate. In this framework, almost all the…

Astrophysics · Physics 2009-11-10 Peng Wang , Xin-He Meng

We study the dynamical behaviour of gauge-invariant linear perturbations in spherically symmetric dust cosmologies including a cosmological constant. In contrast to spatially homogeneous FLRW models, the reduced degree of spatial symmetry…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Sven Meyer , Matthias Bartelmann

The interacting dark matter (IDM) scenario allows for the acceleration of the Universe without Dark Energy. We constrain the IDM model by using the newly revised observational data including $H(z)$ data and Union2 SNe Ia via the Markov…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Shuo Cao , Zong-Hong Zhu , Nan Liang

In this paper, we combine the latest observational data, including the WMAP five-year data (WMAP5), BOOMERanG, CBI, VSA, ACBAR, as well as the Baryon Acoustic Oscillations (BAO) and Type Ia Supernoave (SN) "Union" compilation (307 sample)…

Astrophysics · Physics 2008-11-26 Jun-Qing Xia , Hong Li , Gong-Bo Zhao , Xinmin Zhang

We examine the growth of structure in three different cosmological models with interacting dark matter and vacuum energy. We consider the case of geodesic dark matter with zero sound speed, where the relativistic growing mode in…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-20 Humberto A Borges , David Wands

We present a new class of interacting dark sector models that can address the Hubble tension. Interacting dark radiation (DR) has previously been put forward as a solution to the problem, but this proposal is disfavored by the high-$\ell$…

High Energy Physics - Phenomenology · Physics 2024-11-15 Manuel A. Buen-Abad , Zackaria Chacko , Ina Flood , Can Kilic , Gustavo Marques-Tavares , Taewook Youn

In this study, we explore the impact of the interacting parameter on dark matter in a model resulting from a parametrization of dark energy density. To ensure a model-independent approach, we treat \( r_d \) as a free parameter, avoiding…

General Relativity and Quantum Cosmology · Physics 2025-03-11 Ritika Nagpal , S. K. J. Pacif , Farruh Atamurotov , Rasmikanta Pati

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

We consider a unified model of interacting dark matter and dark energy to account for coincidence of present day dark energy and dark matter densities. We assume dark energy to be represented by a homogeneous scalar field $\phi$ whose…

General Relativity and Quantum Cosmology · Physics 2019-04-29 Abhijit Bandyopadhyay , Anirban Chatterjee

We investigate the impacts of interaction between dark matter and dark energy in the context of two dark energy models, holographic and ghost dark energy. In fact, using the dynamical system analysis, we obtain the cosmological consequence…

General Relativity and Quantum Cosmology · Physics 2017-07-26 Hanif Golchin , Sara Jamali , Esmaeil Ebrahimi

Full suite of the present day Cosmic Microwave background (CMB) data, when combined with weak prior information on the Hubble constant and the age of the Universe, or the Large-Scale structure, provides strong indication for a non-zero…

Astrophysics · Physics 2007-05-23 D. Pogosyan , J. R. Bond , C. R. Contaldi