Tunneling probability for the birth of an universe with radiation in Horava-Lifshitz theory

TL;DR

This paper investigates the quantum tunneling process that could lead to the birth of a homogeneous, isotropic universe with radiation content within Horava-Lifshitz gravity, analyzing how parameters influence the tunneling probability.

Contribution

It introduces a quantum cosmology model in Horava-Lifshitz gravity, deriving the Wheeler-DeWitt equation and calculating tunneling probabilities for universe creation from nothing.

Findings

Tunneling probability depends on radiation energy and HL parameters.

Classical phase portrait reveals various dynamical behaviors.

Quantitative analysis of universe birth likelihood in HL theory.

Abstract

In the present work, we study the birth of a homogeneous and isotropic Friedmann Lemaitre Robertson Walker (FLRW) cosmological model, considering Horava Lifshitz (HL) as the gravitational theory. The matter content of the model is a radiation perfect fluid. In order to study the birth of the universe in the present model, we consider the quantum cosmology mechanism of creation from nothing. In that mechanism, the universe appears after the wavefunction associated to that universe tunnels through a potential barrier. We started studying the classical model. We draw the phase portrait of the model and identify qualitatively all types of dynamical behaviors associated to it. Then, we write the Hamiltonian of the model and apply the Dirac quantization procedure to quantize a constrained theory. We find the appropriate Wheeler-DeWitt equation and solve it using the Wentzel Kramers Brillouin (WKB) approximation. Using the WKB solution, to the Wheeler DeWitt equation, we compute the tunneling probabilities for the birth of that universe (TPWKB). Since the WKB wavefunction depends on the radiation energy (E) and the free parameters coming from the HL theory (gc, gr, gs, gLambda), we compute the behavior of TPWKB as a function of E and all the HL parameters gc, gr, gs, gLambda.