The Cosmological Constant Problem from the Point of View of String Theory

TL;DR

This paper explores how string theory and extra dimensions can naturally produce a small cosmological constant, potentially explaining the universe's accelerated expansion and addressing the discrepancy between quantum predictions and observations.

Contribution

It introduces a method to calculate the cosmological constant within string theory, showing how scalar fields from extra dimensions can yield values consistent with observations.

Findings

Scalar field from extra dimensions can produce a small cosmological constant.

Calculated values are significantly lower than traditional quantum field theory estimates.

Discussion on how this approach explains the universe's accelerated expansion.

Abstract

The quantum field theory prediction of the cosmological constant is 120 orders of magnitude higher than the observed value. This is known as the cosmological constant problem. Here, we deal with the cosmological constant as a scalar field generated by the reduced extra dimensions, following Kaluza-Klein reduction, in the superstring theory frame, where the vacuum energy is the minimum of this field. We find methods for calculating the cosmological constant, whose value is much lower than those obtained with the current methods of quantum field theory. We conclude that the small cosmological constant value could be explained by the behavior of the mentioned scalar field, and finally we discuss a possible explanation for the observed accelerated expansion of the Universe.