2015/05/28 by P. Castorina, Paolo Castorina, Vincenzo Greco +1
Physics and Astronomy · #Acceleration #Astrophysics #Baryon #Cosmology #Cosmology and Gravitation Theories #Dark energy #De Sitter universe #Deceleration parameter #Electroweak interaction #Equation of state #High-Energy Particle Collisions Research #Jerk #Mathematical physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum chromodynamics #Quantum mechanics #Quark–gluon plasma #Universe #astro-ph.CO #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.92.063530
published as Phys. Rev. D 92, 063530 (2015)
arxiv created 2015/05/28 · openalex publication_date 2015/09/22 · arxiv updated 2015/09/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The time evolution of cosmological parameters in the early Universe at the deconfinement transition is studied by an equation of state (EoS) which takes into account the finite baryon density and the background magnetic field. The nonperturbative dynamics is described by the field correlator method which gives, with a small number of free parameters, a good fit of lattice data. The entire system has two components, i.e., the quark-gluon plasma and the electroweak sector, and the solutions of the Friedmann equation show that the scale factors a(t) and H(t)=(1/a)da/dt are weakly dependent on the EoS, but the deceleration parameter q(t) and the jerk j(t) are strongly modified above the critical temperature Tc, corresponding to a critical time tc\ensuremath≃20--25 \ensuremathμs. The time evolution of the cosmological parameters suggests that above and around Tc, there is a transient state of acceleration typical of a matter-dominated universe; this is entailed by the QCD strong interaction. The effect of the hadronic matter below Tc does not qualitatively change the previous behavior and one can consistently follow the cosmological evolution up to 100 \ensuremathμs.