Cosmological Time, Entropy and Infinity

TL;DR

This paper proposes a novel cosmological model where the flow of time depends on the universe's entropy, leading to accelerated expansion without dark energy, and avoids infinities by assuming a finite, closed universe.

Contribution

It introduces a new hypothesis linking cosmological time to entropy, enabling models with acceleration and finiteness without dark energy or infinite values.

Findings

Models exhibit accelerated expansion without dark energy.

Universe can be finite and spatially closed.

Time flow correlates with entropy of causally connected regions.

Abstract

Time is a parameter playing a central role in our most fundamental modelling of natural laws. Relativity theory shows that the comparison of times measured by different clocks depends on their relative motion and on the strength of the gravitational field in which they are embedded. In standard cosmology, the time parameter is the one measured by fundamental clocks (i.e., clocks at rest with respect to the expanding space). This proper time is assumed to flow at a constant rate throughout the whole history of the universe. We make the alternative hypothesis that the rate at which the cosmological time flows depends on the dynamical state of the universe. In thermodynamics, the arrow of time is strongly related to the second law, which states that the entropy of an isolated system will always increase with time or, at best, stay constant. Hence, we assume that the time measured by fundamental clocks is proportional to the entropy of the region of the universe that is causally connected to them. Under that simple assumption, we find it possible to build toy cosmological models that present an acceleration of their expansion without any need for dark energy while being spatially closed and finite, avoiding the need to deal with infinite values.