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Related papers: Metastable Dark Energy with Radioactive-like Decay

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We consider a cosmology with decaying metastable dark energy and assume that a decay process of this metastable dark energy is a quantum decay process. Such an assumption implies among others that the evolution of the Universe is…

General Relativity and Quantum Cosmology · Physics 2019-09-27 Aleksander Stachowski , Marek Szydlowski , Krzysztof Urbanowski

The metastable dark energy scenario is revisited by assuming that the current false vacuum energy density is the remnant from a primeval inflationary stage. The zero temperature scalar field potential is here described by an even power…

General Relativity and Quantum Cosmology · Physics 2020-09-01 J. A. S. Lima , G. J. M. Zilioti , L. C. T. Brito

We investigate constraints on some key cosmological parameters by confronting metastable dark energy models with different combinations of the most recent cosmological observations. Along with the standard $\Lambda$CDM model, two…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-14 Xiaolei Li , Arman Shafieloo , Varun Sahni , Alexei A. Starobinsky

We build a model of metastable dark energy, in which the observed vacuum energy is the value of the scalar potential at the false vacuum. The scalar potential is given by a sum of even self-interactions up to order six. The deviation from…

High Energy Physics - Phenomenology · Physics 2016-12-02 Ricardo G. Landim , Elcio Abdalla

In this letter we consider a dark energy model in which the energy density is a function of the Hubble parameter $H$ and its derivative with respect to time $\rho_{de}=3\alpha \ddot{H}H^{-1}+3\beta\dot{H}+3\gamma H^2$. The behavior of the…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Songbai Chen , Jiliang Jing

We use data from observational cosmology to put constraints on higher-dimensional extensions of general relativity in which the effective four-dimensional dark-energy density (or cosmological "constant") decays with time. In particular we…

Astrophysics · Physics 2009-11-13 J. M. Overduin , P. S. Wesson , B. Mashhoon

We derive the Shafieloo, Hazra, Sahni and Starobinsky (SHSS) phenomenological formula for the radioactive-like decay of metastable dark energy directly from the quantum mechanics principles. For this aim we use the Fock-Krylov theory of…

General Relativity and Quantum Cosmology · Physics 2018-05-22 Marek Szydlowski , Aleksander Stachowski , Krzysztof Urbanowski

We revisit a cosmological model where dark matter (DM) and dark energy (DE) follow barotropic equations of state, allowing deviations from the standard $\Lambda$CDM framework (i.e. $w_{dm} \neq 0$, $w_{de} \neq -1$), considering both flat…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-24 Dorian Araya , Cristian Castillo , Genly Leon , Juan Magaña , Angie Barr Domínguez , Miguel A. García-Aspeitia

Early dark energy (EDE) models are a class of quintessence dark energy with a dynamically evolving scalar field which display a small but non-negligible amount of dark energy at the epoch of matter-radiation equality. Compared with a…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-02 Difu Shi , Carlton M. Baugh

Current observational data indicate that dark energy (DE) is a cosmological constant without considering its conclusiveness evidence. Considering the dynamic nature of $\Lambda$ individually as a function of time and the scale factor, we…

General Relativity and Quantum Cosmology · Physics 2023-11-07 Jafar Khodagholizadeh

If dark matter (DM) is unstable, in order to be present today, its lifetime needs to be longer than the age of the Universe, t_U ~ 4 10^{17} s. It is usually assumed that if DM decays it would do it with some strength through a radiative…

Astrophysics · Physics 2009-06-23 Sergio Palomares-Ruiz

In this work, we investigate two Dark Energy (DE) models characterized by higher-order derivatives of the Hubble parameter $H$, which generalize previously proposed DE scenarios. Assuming a power-law form of the scale factor $a(t)$ given by…

General Relativity and Quantum Cosmology · Physics 2025-10-14 Antonio Pasqua

In this paper, we consider a recently proposed model of Dark Energy (DE) which contains three terms (one proportional to the squared Hubble parameter, one to the first derivative with respect to the cosmic time of the Hubble parameter and…

General Physics · Physics 2013-09-13 Antonio Pasqua , Surajit Chattopadhyay , Ratbay Myrzakulov

A $\Lambda$CDM model with dark matter that decays into inert relativistic energy on a timescale longer than the Hubble time will produce an expansion history that can be misinterpreted as stable dark matter with time-varying dark energy. We…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-27 Sourish Dutta , Robert J. Scherrer

Decaying Dark Energy models modify the background evolution of the most common observables, such as the Hubble function, the luminosity distance and the Cosmic Microwave Background temperature-redshift scaling relation. We use the most…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-05 Ivan de Martino

In this work we examine the possibility that the dark energy (DE) density, $\rho_{de}$ can be dynamical and appear as a power series expansion of the Hubble rate (and its derivatives), i.e.$\rho_{de}(H,\dot{H},...)$. For the present…

General Relativity and Quantum Cosmology · Physics 2019-07-30 Mehdi Rezaei , Mohammad Malekjani , Joan Sola

High precision cosmological observations in last decade suggest that about 70% of our universe's energy density is in so called "Dark Energy" (DE). Observations show that DE has negative effective pressure and therefore unlike conventional…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-01 Lado Samushia

We explore the fate of the universe given the possibility that the density associated with `dark energy' may decay slowly with time. Decaying dark energy is modeled by a homogeneous scalar field which couples minimally to gravity and whose…

Astrophysics · Physics 2009-11-07 Ujjaini Alam , Varun Sahni , A. A. Starobinsky

The nature of dark energy (DE) remains elusive, even though it constitutes the dominant energy-density component of the Universe and drives the late-time acceleration of cosmic expansion. By combining measurements of the expansion history…

We study the evidence for dark energy (DE) evolution at low redshift, using baryonic acoustic oscillations (BAOs) from the DESI Early Data Release, Pantheon+ Type Ia supernovae (SNe-Ia), and redshift space distortions (RSDs) to constrain…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-30 Lili Orchard , Víctor H. Cárdenas
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