Numerical Evaluation of Tunneling Probabilities for the Birth of Universes with Radiation, Cosmological Constant, and Ad-hoc Potential.

Oliveira-Neto et al. (Eur. Phys. J. Plus 138, 400 2023) recently investigated the birth of Friedmann-Lemaïtre-Robertson-Walker (FLRW) universes with flat ( k = 0 ) and hyperbolic ( k = - 1 ) curvatures of their spatial sections, with material contents composed of radiation, a positive cosmological constant and an ad-hoc potential, solving the Wheeler-DeWitt equation and calculating tunneling probabilities for the birth of those universes as functions not only of the wave packet energy, but also of the system parameters, via the semi-classical WKB approximation. In this article we review that analysis using a more general and accurate numerical method for calculating tunneling probabilities. Larger probabilities than those obtained by the WKB approximation have been obtained for the birth of such universes. [ABSTRACT FROM AUTHOR]