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The quark-gluon to hadron transition affects the evolution of cosmological perturbations. If the phase transition is first order, the sound speed vanishes during the transition, and density perturbations fall freely. This distorts the…

Astrophysics · Physics 2008-11-26 Christoph Schmid , Dominik J. Schwarz , Peter Widerin

We investigate the effect of the cosmological QCD transition on the evolution of primordial density perturbations. If the phase transition is first order, the sound speed vanishes during the transition and density perturbations fall freely.…

Astrophysics · Physics 2007-05-23 Dominik J. Schwarz , C. Schmid , P. Widerin

The cosmological QCD transition affects primordial density perturbations. If the QCD transition is first order, the sound speed vanishes during the transition and density perturbations fall freely. For scales below the Hubble radius at the…

Astrophysics · Physics 2009-10-30 Christoph Schmid , Dominik J. Schwarz , Peter Widerin

The cosmological QCD transition affects primordial density perturbations. If the QCD transition is first order, the sound speed vanishes during the transition and density perturbations fall freely. For scales below the Hubble radius at the…

Astrophysics · Physics 2007-05-23 Dominik J. Schwarz , Christoph Schmid , Peter Widerin

We propose that the amplified density fluctuations by the vanishing sound velocity effect during the cosmological quark-hadron phase transition lead to quark-gluon plasma lumps decoupled from the expansion of the universe, which may evolve…

Astrophysics · Physics 2009-10-31 Hee Il Kim , Bum-Hoon Lee , Chul H. Lee

The cosmological evolution can be described in terms of directly measurable cosmological scalar parameters (deceleration $q$, jerk $j$, snap $s$, etc...) constructed out of high order derivatives of the scale factor. Their behavior at the…

High Energy Physics - Phenomenology · Physics 2018-07-18 P. Castorina , D. Lanteri , S. Mancani

In the standard picture of cosmology it is predicted that a phase transition, associated with chiral symmetry breaking after the electroweak transition, has occurred at approximately 10 \mu seconds after the Big Bang to convert a plasma of…

High Energy Physics - Theory · Physics 2015-05-13 K. Atazadeh , A. M. Ghezelbash , H. R. Sepangi

We investigate the effects of the sharpness of the phase transition between hadronic matter and quark matter on various properties of neutron stars. We construct hybrid equations of state by combining a hadronic model with a quark model…

Nuclear Theory · Physics 2025-10-03 M. B. Albino , R. Fariello , G. Lugones , F. S. Navarra

In the model of a first order quark-gluon/hadron phase transition in which the hadronic phase is considered as vacuum bubbles growing in the quark-gluon background with chiral symmetry broken inside the bubble, we find the estimate for the…

High Energy Physics - Phenomenology · Physics 2009-10-28 L. Burakovsky

We study the phase transition from quark-gluon plasma to hadrons in the early universe in the context of non-equilibrium thermodynamics. According to the standard model of cosmology, a phase transition associated with chiral symmetry…

General Relativity and Quantum Cosmology · Physics 2015-06-19 M. Khodadi , H. R. Sepangi

A standard picture in cosmology has been emerging over the past decade in which a phase transition, associated with chiral symmetry breaking after the electroweak transition, has occurred at approximately $10^{-6}$ seconds after the Big…

General Relativity and Quantum Cosmology · Physics 2011-04-04 K. Atazadeh , A. M. Ghezelbash , H. R. Sepangi

Based on hot big bang theory, the cosmological matter is conjectured to undergo QCD phase transition(s) to hadrons, when the universe was about $1-10 \mu$s old. In the present work, we study the quark-hadron phase transition, by taking into…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-26 A. Tawfik , T. Harko

The last phase transition predicted by the standard model of particle physics took place at the QCD scale $T\sim200$ MeV when the universe was about $t\sim10^{-5}$ seconds old and the Hubble radius was around 10 Km. In this paper, we…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Malihe Heydari-Fard , Hamid Reza Sepangi

Baryon number inhomogeneities may be generated during the epoch when the baryon asymmetry of the universe is produced, e.g. at the electroweak phase transition. The regions with excess baryon number will have a lower temperature than the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Soma Sanyal

It is entirely plausible that during the primordial quark-hadron transition, microseconds after the Big Bang, the universe may experience supercooling accompanied by mini inflation leading to a first-order phase transition from quarks to…

General Physics · Physics 2020-05-13 Bikash Sinha

We explore the effect of relic gravitational waves on the primordial phase change from the quark-gluon plasma into the low density hadron gas that occurred approximately $10^{-5}$s after the beginning. We show that the gravitational wave,…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-01 Raymond Angélil , Prasenjit Saha , Jürg Diemand

We study the dynamics of first-order phase transition in the early Universe when it was $10-50 \mu s$ old with quarks and gluons condensing into hadrons. We look at how the Universe evolved through the phase transition in small as well as…

High Energy Physics - Phenomenology · Physics 2009-10-31 Deepak Chandra , Ashok Goyal

We study the dynamics of the quark-hadron transition for a scenario in which the Universe is matter dominated and a large amount of entropy is generated by decaying particles of mass 1--10 TeV, as suggested by a large class of…

High Energy Physics - Phenomenology · Physics 2009-10-22 Ornella Pantano , Antonio Riotto

The recent claim by the NANOGrav collaboration of a possible detection of an isotropic gravitational wave background stimulated a series of investigations searching for the origin of such a signal. The QCD phase transition appears as a…

High Energy Physics - Phenomenology · Physics 2021-08-25 Pauline Lerambert-Potin , Jose Antonio de Freitas Pacheco

Studies of the growth of cosmic perturbations are typically focused on galactic scales and above. In this paper we investigate the evolution of perturbations in baryons, photons, and dark matter for masses below 10^6 M_\odot (or wavenumbers…

Astrophysics · Physics 2009-11-07 Shwetabh Singh , Chung-Pei Ma
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