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arXiv · 1711.08317

Light meson gas in the QCD vacuum and oscillating Universe

George Prokhorov·Roman Pasechnik
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Abstract

We have developed a phenomenological effective quantum-field theoretical model describing the "hadron gas" of the lightest pseudoscalar mesons, scalar {\sigma}-meson and {\sigma}-vacuum, i.e. the expectation value of the {\sigma}-field, at finite temperatures. The corresponding thermodynamic approach was formulated in terms of the generating functional derived from the effective Lagrangian providing the basic thermodynamic information about the "meson plasma + QCD condensate" system. This formalism enables us to study the QCD transition from the hadron phase with direct implications for cosmological evolution. Using the hypothesis about a positively-definite QCD vacuum contribution stochastically produced in early universe, we show that the universe could undergo a series of oscillations during the QCD epoch before resuming unbounded expansion.

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George Prokhorov, Roman Pasechnik. 2017-11-22. Light meson gas in the QCD vacuum and oscillating Universe. https://doi.org/10.1088/1475-7516%2F2018%2F01%2F017

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