Thermal Vacuum Model for Cosmology without Inflaton

Abstract

The previously proposed modification of the standard (flat) inflationary $ΛCDM$ model in which the inflaton field(s) and ``dark energy" are replaced by the vacum in expanding Friedmann-Lemaître-Robertson-Walker Universe is studied. The expanding joint vacuum of the all ingrediences of matter, including Standard Model particles and a dark matter sector, is treated as a thermal equilibrium state at temporal Gibbons-Hawking temperature, proportional to the Hubble parameter, and chemical potentials equal to particle masses. This theory provides not only the new mechanism of inflation and its graceful exit, but also explains acceleration of expansion for the late Universe. The formalism can be combined with the anomalous quantum gravity effects leading to a viable baryogenesis mechanism and certain bounds on dark matter particle masses and lifetimes.

Figures (2)

• Figure 1: Early cosmological history based on the solutions to \ref{['eq:1FE1']} for the initial condition $h(0) = h_0(1 - 10^{-9})$. The rescaled dimensionless time $\tau = h_0 t$ and the dimensionless Hubble parameter $\tilde{h} = h/h_0$ are used here. The quantities plotted are : the rescaled TV energy density $\tilde{\rho}_{\rm dS}= \frac{3}{8\pi} \tilde{h}^4$, and the rescaled matter energy density $\tilde{\rho}_r = \frac{3}{8\pi}(\tilde{h}^2 - \tilde{h}^4)$. The curves cross at $\tau_c = h_0 t_c$ when matter is in equilibrium with TV and the Hot Big Bang begins.
• Figure 2: Plots of the $f(z)$ curves given by: a) \ref{['eq:f_eq']} with $\Gamma = 0.40 , 0.45 , 0.50$; b), \ref{['eq:h_LCDM']} with $\Omega_{\Lambda} =0.7$; c) \ref{['eq:f_matter']}