1. Metastable Dark Energy with Radioactive-like Decay
- Author
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Dhiraj Kumar Hazra, Arman Shafieloo, Varun Sahni, Alexei A. Starobinsky, Korea Astronomy and Space Science Institute (KASI), University of Science and Technology [Daejeon] (UST), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Inter-University Centre for Astronomy and Astrophysics [Pune] (IUCAA), L.D. Landau Institute for Theoretical Physics of RAS, Russian Academy of Sciences [Moscow] (RAS), Joint Institute for Nuclear Research (JINR), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)
- Subjects
cosmological model ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,quasar: redshift ,Scalar field dark matter ,FOS: Physical sciences ,General Relativity and Quantum Cosmology (gr-qc) ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,General Relativity and Quantum Cosmology ,dark matter ,Thermodynamics of the universe ,High Energy Physics - Phenomenology (hep-ph) ,De Sitter universe ,cosmology: theory ,0103 physical sciences ,energy: density ,dark energy ,010303 astronomy & astrophysics ,Light dark matter ,Physics ,decay rate ,Hubble constant ,[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] ,010308 nuclear & particles physics ,Hot dark matter ,redshift: high ,nucleus ,Astronomy and Astrophysics ,High Energy Physics - Phenomenology ,dark energy: decay ,Space and Planetary Science ,Dark radiation ,radioactivity ,curvature ,Dark energy ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Dark fluid ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We propose a new class of metastable dark energy (DE) phenomenological models in which the DE decay rate does not depend on external parameters such as the scale factor or the curvature of the Universe. Instead, the DE decay rate is assumed to be a constant depending only on intrinsic properties of DE and the type of a decay channel, similar to case of the radioactive decay of unstable particles and nuclei. As a consequence, the DE energy density becomes a function of the proper time elapsed since its formation, presumably in the very early Universe. Such a natural type of DE decay can profoundly affect the expansion history of the Universe and its age. Metastable DE can decay in three distinct ways: (i) exponentially, (ii) into dark matter, (iii) into dark radiation. Testing metastable DE models with observational data we find that the decay half-life must be many times larger than the age of the Universe. Models in which dark energy decays into dark matter lead to lower values of the Hubble parameter at large redshifts relative to $\Lambda$CDM. Consequently these models provide a better fit to cosmological BAO data (especially data from from high redshift quasars) than concordance ($\Lambda$CDM) cosmology., Comment: 12 pages, 8 figures, 2 tables, matches the final version published in MNRAS
- Published
- 2018