English
Related papers

Related papers: Unimodular Diffusion and Interacting Vacuum Cosmol…

200 papers

Even though the Dark Energy Spectroscopic Instrument (DESI) mission does not exclude a dynamical dark energy evolution, the concordance paradigm, i.e., the $\Lambda$CDM model, remains statistically favored, as it depends on the fewest…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-08 Anna Chiara Alfano , Orlando Luongo , Marco Muccino

In the context of a homogeneous and isotropic universe, we consider the degeneracy condition at the background level between two scenarios in which processes out of equilibrium are possible; this consideration allows us to deviate from the…

General Relativity and Quantum Cosmology · Physics 2025-03-05 Gilberto Aguilar-Pérez , Ana A. Avilez-López , Miguel Cruz

We investigate the characteristic modifications in the evolving cosmological perturbations when dark energy interacts with dust-like matter, causing the latter's background energy density fall off with time faster than usual. Focusing in…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-06 Mohit Kumar Sharma , Sourav Sur

By embedding discrete representations into a continuous latent space, we can leverage continuous-space latent diffusion models to handle generative modeling of discrete data. However, despite their initial success, most latent diffusion…

Machine Learning · Computer Science 2025-04-02 Bac Nguyen , Chieh-Hsin Lai , Yuhta Takida , Naoki Murata , Toshimitsu Uesaka , Stefano Ermon , Yuki Mitsufuji

We propose a mechanism for generating an inflationary phase in the early universe without resorting to any type of scalar field(s). Instead, this accelerated expansion is driven by a dynamical "cosmological constant" in the framework of…

General Relativity and Quantum Cosmology · Physics 2022-03-18 Gabriel Leon

We study the bulk flow of the local universe using Type Ia supernova data by considering a class of cosmological model which is spatially flat,(FRW) space-times and contains cold dark matter and $Q$ component (QCDM models) of the fluid as a…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-31 A. Salehi , M. Yarahmadi , S. Fathi

We extend the holographic Ricci dark energy model to include some direct, non-gravitational interaction between dark energy and dark matter. We consider three phenomenological forms for the interaction term $Q$ in the model, namely, $Q$ is…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-10 Tian-Fu Fu , Jing-Fei Zhang , Jin-Qian Chen , Xin Zhang

In this paper, we introduce a novel class of interacting vacuum models, based on recasting the equation of state originally developed in the context of lattice kinetic theory by Shan \& Chen as the coupling between the vacuum and cold dark…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-01 Natalie B. Hogg , Marco Bruni

We study in some detail an interacting cosmological model based on two canonical scalar fields starting from a Lagrangian description. Contrary to other more phenomenological approaches where non-relativistic matter and dark energy are…

General Relativity and Quantum Cosmology · Physics 2021-10-20 Grigoris Panotopoulos , Ilídio Lopes

In this paper, we introduce a new interacting mechanism within the dark sector, encompassing both dark energy and dark matter, while grounding our analysis in the familiar framework of the $\mathrm{\Lambda CDM}$ model augmented by baryons…

General Relativity and Quantum Cosmology · Physics 2025-08-13 Martín G. Richarte , Luiz F. Guimarães , Susana J. Landau , Júlio C. Fabris

Non-canonical scaling of the form $\rho_{x} \propto \rho_{m} a^{\xi}$, where $\rho_{x}$ and $\rho_{m}$ are the energy densities of dark energy and dark matter, respectively, provides a natural way to address the coincidence problem -why the…

Astrophysics · Physics 2009-11-10 Diego Pavon , Somasri Sen , Winfried Zimdahl

Motivated by the fact that any nonzero $\Lambda$ can introduce a length scale or a time scale into Einstein's theory, $r_{\Lambda}=ct_{\Lambda}=\sqrt{3/|\Lambda|}$. Conversely, any cosmological length scale or time scale can introduce a…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-04 Yun Chen , Zong-Hong Zhu , Lixin Xu , J. S. Alcaniz

We consider the cosmological dynamics of the cubic Galileon field model interacting with dark matter, where the interaction between the cosmic dark sectors is proportional to Hubble parameter and dark energy density. The background field…

General Relativity and Quantum Cosmology · Physics 2018-07-03 Sihem Zaabat , Khireddine Nouicer

We consider an interacting field theory model that describes the dark energy - dark matter interaction. Only for a specific interaction term, this interacting field theory description has an equivalent interacting fluid description. For…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-26 Joseph P Johnson , Archana Sangwan , S. Shankaranarayanan

The current observational tensions in the standard cosmological model have reinforced the research on dynamical dark energy, in particular on models with non-gravitational interaction between the dark components. Analyses of late-time…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-26 M. Benetti , P. T. Z. Seidel , C. Pigozzo , I. P. R. Baranov , S. Carneiro , J. C. Fabris

In this work we study a phenomenological non-gravitational interaction between dark matter and dark energy. The scenario studied in this work extends the usual interaction model proportional to the derivative of the dark component density…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-14 Josue De-Santiago , Iván E. Sánchez G. , David Tamayo

We present improved constraints on an interacting vacuum model using updated astronomical observations including the first data release from Planck. We consider a model with one dimensionless parameter, $\alpha$, describing the interaction…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-09 Yuting Wang , David Wands , Gong-Bo Zhao , Lixin Xu

The coupling between dark sectors provides a possible approach to mitigate the coincidence problem of cosmological standard model. In this paper, dark energy is treated as a fluid with a constant equation of state, whose coupling with dark…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-15 Weiqiang Yang , Lixin Xu

We extend the results of a previous paper where a model of interacting dark energy, with a cosmological term decaying linearly with the Hubble parameter, is tested against the observed mass power spectrum. In spite of the agreement with…

Astrophysics · Physics 2008-12-30 H. A. Borges , S. Carneiro , J. C. Fabris

The standard cosmological model currently in force, aka $\Lambda$CDM, has been plagued with a variety of tensions in the last decade or so, which puts it against the wall. At the core of the $\Lambda$CDM we have a rigid cosmological term,…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-19 Adria Gómez-Valent , Joan Solà Peracaula
‹ Prev 1 4 5 6 7 8 10 Next ›