Quantum Gravity, the Origin of Time and Time's Arrow

TL;DR

This paper proposes a model where spontaneous symmetry breaking in the early Universe generates time and matter, explaining the origin of the arrow of time through a Higgs mechanism and phase transition.

Contribution

It introduces a Higgs mechanism in quantum gravity that explains the emergence of time, matter creation, and the cosmological arrow of time during the early Universe.

Findings

Time is generated by spontaneous symmetry breaking.

Matter is created after the phase transition.

The arrow of time aligns with symmetry restoration at low temperatures.

Abstract

The local Lorentz and diffeomorphism symmetries of Einstein's gravitational theory are spontaneously broken by a Higgs mechanism by invoking a phase transition in the early Universe, at a critical temperature $T_c$ below which the symmetry is restored. The spontaneous breakdown of the vacuum state generates an external time and the wave function of the Universe satisfies a time dependent Schrodinger equation, which reduces to the Wheeler-deWitt equation in the classical regime for $T < T_c$, allowing a semi-classical WKB approximation to the wave function. The conservation of energy is spontaneously violated for $T > T_c$ and matter is created fractions of seconds after the big bang, generating the matter in the Universe. The time direction of the vacuum expectation value of the scalar Higgs field generates a time asymmetry, which defines the cosmological arrow of time and the direction of increasing entropy as the Lorentz symmetry is restored at low temperatures.