Gravity effects of the quantum vacuum. Dark energy and dark matter

TL;DR

This paper investigates the quantum vacuum's stress-energy tensor in QED, proposing it contributes to dark energy and dark matter through vacuum fluctuations that modify spacetime and balance the cosmological constant.

Contribution

It introduces a model where vacuum fluctuations in QED produce effects that can explain dark energy and dark matter, linking quantum vacuum properties to cosmological phenomena.

Findings

Vacuum stress-energy tensor is approximately proportional to the metric tensor.

Vacuum fluctuations can modify spacetime to account for dark energy.

Certain vacuum excitations may explain dark matter.

Abstract

The stress-energy tensor of the quantum vacuum is studied for the particular case of quantum electrodynamics (QED), that is a fictituous universe where only the electromagnetic and the electron-positron fields exist. The integrals involved are ultraviolet divergent but it is suggested that a natural cut-off may exist. It is shown that, in spite of the fact that the stress-energy tensor of the electromagnetic field alone is traceless (i.e the pressure P equals 1/3 the energy density u), the total QED tensor is proportional to the metric tensor to a good approximation (i. e. P = -u). It is proposed that there is a cosmological constant in Einstein equation that exactly balances the stress-energy of the vacuum. It is shown that vacuum fluctuations give rise to a modified spacetime metric able to explain dark energy. Particular excitations of the vacuum are studied that might explain dark matter.