Interpreting cosmological vacuum decay
By J. Alcaniz, J. A. S. Lima. 2005
139 citations recorded by the source corpus.
The cosmological vacuum decay scenario recently proposed by Wang and Meng [Classical Quantum Gravity 22, 283 (2005)] is rediscussed. From thermodynamic arguments it is found that the $ϵ$ parameter quantifying the vacuum decay rate must be positive in the presence of particle creation. If there is no particle creation, the proper mass of Cold Dark Matter (CDM) particles is necessarily a time-dependent quantity, scaling as $m(t)={m}_{o}a(t{)}^{ϵ}$. By considering the presence of baryons in the cosmological scenario, it is also shown that their dynamic effect is to alter the transition redshift ${z}_{*}$ (the redshift at which the Universe switches from decelerating to accelerating expansion), predicting values of ${z}_{*}$ compatible with current estimates based on type Ia supernova. In order to constrain the ${\ensuremath{\Omega}}_{m}\ensuremath{-}ϵ$ plane, a joint statistical analysis involving the current supernovae observations, gas mass fraction measurements in galaxy clusters and CMB data is performed. At $95%$ c.l. it is found that the vacuum decay rate parameter lies on the interval $ϵ=0.06\ifmmode\pm\else\textpm\fi{}0.10$. The possibility of a vacuum decay into photons is also analyzed. In this case, the energy density of the radiation fluid scales as ${\ensuremath{\rho}}_{r}={\ensuremath{\rho}}_{ro}{a}^{\ensuremath{-}4+ϵ}$, and its temperature evolution law obeys $T(t)={T}_{o}a(t{)}^{ϵ/4\ensuremath{-}1}$.
Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/929ae31d780d66d857131d0cc1c64d74b2b63b7b
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In Astronomy and Astrophysics
- S. Basilakos
- J. Solà
- J. V. Cunha
- J. A. S. Lima
- A. Gómez-Valent
- T. Dereli
- Özgür Akarsu
- Javier de Cruz Pérez
In Nuclear and High Energy Physics
Citations in the corpus
- Expansion History with Decaying Vacuum: A Complete Cosmological Scenario (2012, background): “…1998) and even more recently (Shapiro & Solà 2000; Shapiro & Solà 2002; Alcaniz & Maia 2003; Opher & Pellison 2004; Bauer 2005; Carneiro & Lima 2005; Alcaniz & Lima 2005; Barrow & Clifton 2006; Montenegro & Carneiro 2007; Shapiro & Solà 2009; Solà & Štefančić 2005, 2006; Basilakos 2009;…”
- Transition redshift: new kinematic constraints from supernovae (2008, background): “…et al. 1992; Lima & Maia 1993; 1994; Maia & Lima 1999; 2002; Lima 1996; Overduin & Cooperstock 1998; Cunha et al. 2002a,b; Cunha & Santos 2004; Alcaniz & Lima 2005; Carneiro & Lima 2005; Fabris et al. 2007), a time varying relic scalar field slowly rolling down its potential (Ratra & Peebles…”