Continuous matter creation and the acceleration of the universe: the growth of density fluctuations

Abstract

Cosmologies including continuous matter creation are able to reproduce the main properties of the standard ΛCDM model, in particular in cases where the particle and entropy production rates are equal. These specific models, characterized by a mass density equal to the critical value, behave like the standard ΛCDM model at early times whereas their late evolution is similar to the steady-state cosmology. The maximum amplitude of density fluctuations in these models depends on the adopted creation rate, related here to the parameter v and this limitation could be a difficulty for the formation of galaxies and large-scale structure in this class of universe. Additional problems are related with predictions either of the random peculiar velocities of galaxies or the present density of massive clusters of galaxies, both being largely overestimated with respect to observational data.

Accelerated expansion of the universe based on particle creation–destruction processes and dark energy in FLRW universes

“…Taking into account thatṅ n = Γ − 3H, equation 18 is finally expressed as equation 19, which matches the one obtained by other authors [23]…”

Note on “Continuous matter creation and the acceleration of the universe: the growth of density fluctuations”

“…In conclusion, we have shown that the Newtonian analysis performed by de Roany and Pacheco [1] fails when trying to recover the background (zero order) relativistic model proposed in Ref. [2].…”

“…At this point, we stress that the original notation of [2] will be adopted. In the notation of [1], α is represented by Ω v .…”

Small-Bang versus Big-Bang Cosmology

“…Instead we can say that we are the result of an initial small bang, just after inflation of an initial fluctuation, an initial quantum black hole whose inflation a little later decelerated. But this deceleration was overcome by the push of the creation pressure, the continuous creation of matter [2], [3], [4] and [5]. As we will see, most physicals properties of the universe are subject to this increase with time.…”