A darkless space-time

TL;DR

This paper proposes a novel model of spacetime as a material continuum with defects, explaining cosmic inflation and acceleration without dark matter or dark energy by using a viscosity-like field linked to spacetime defects.

Contribution

It introduces a spacetime model based on continuum mechanics with defects, providing a new explanation for cosmic acceleration without dark components.

Findings

Model reproduces inflation and accelerated expansion.

Parameter can be fixed to match observed acceleration.

Adding matter does not alter the core behavior.

Abstract

In cosmology it has become usual to introduce new entities as dark matter and dark energy in order to explain otherwise unexplained observational facts. Here, we propose a different approach treating spacetime as a continuum endowed with properties similar to the ones of ordinary material continua, such as internal viscosity and strain distributions originated by defects in the texture. A Lagrangian modeled on the one valid for simple dissipative phenomena in fluids is built and used for empty spacetime. The internal "viscosity" is shown to correspond to a four-vector field. The vector field is shown to be connected with the displacement vector field induced by a point defect in a four-dimensional continuum. Using the known symmetry of the universe, assuming the vector field to be divergenceless and solving the corresponding Euler-Lagrange equation, we directly obtain inflation and a phase of accelerated expansion of spacetime. The only parameter in the theory is the "strength" of the defect. We show that it is possible to fix it in such a way to also quantitatively reproduce the acceleration of the universe. We have finally verified that the addition of ordinary matter does not change the general behaviour of the model.