String Phenomenology and the Cosmological Constant

TL;DR

The paper argues that classical string solutions with a positive cosmological constant are unlikely to be valid due to quantum corrections, which may negate the need for ad hoc uplifting and complicate MSSM parameter calculations.

Contribution

It introduces the idea that quantum effects in string theory could naturally eliminate the need for uplifting to achieve a positive CC, challenging existing assumptions.

Findings

Quantum corrections negate classical positive CC solutions.

No need for ad hoc uplifting terms in string models.

Reevaluation of MSSM parameter calculations is required.

Abstract

It is argued that classical string solutions should not be fine tuned to have a positive cosmological constant (CC) at the observed size, since even the quantum corrections from standard model effects will completely negate any classical string theory solution with such a CC. In fact it is even possible that there is no need at all for any ad hoc uplifting term in the potential since these quantum effects may well take care of this. Correspondingly any calculation of the parameters of the MSSM has to be rethought to take into account the evolution of the CC. This considerably complicates the issue since the initial conditions for RG evolution of these parameters are determined by the final condition on the CC! The Anthropic Principle is of no help in addressing these issues.