[Paper Review] Radiative Generation of dS from AdS.

de Alwis|arXiv (Cornell University)|Oct 13, 2021

Black Holes and Theoretical Physics1 references4 citations

TL;DR

This paper proposes that radiative corrections in type IIB string compactifications within the large volume scenario can generate a positive cosmological constant (CC) despite a negative string-theoretic CC, provided mild spectral conditions on low-energy modes are met. This challenges the de Sitter swampland conjecture by showing it may not be physically relevant at low energies.

ABSTRACT

The large volume scenario (LVS) of type IIB string compactifications has a robust supersymmetry breaking minimum with a negative cosmological constant (CC). We argue that radiative corrections below the Kaluza-Klein (KK) scale can result in a positive CC, though the string theory generated CC is negative, if some mild conditions on the spectrum of low energy fluctuations are satisfied. This would make the so-called deSitter swampland conjecture (even if true at a high scale) physically irrelevant.

Motivation & Objective

• To investigate whether radiative corrections below the Kaluza-Klein scale can lead to a positive cosmological constant in the large volume scenario of type IIB string compactifications.
• To assess the physical viability of the de Sitter swampland conjecture in light of quantum corrections in string theory.
• To identify the minimal spectral conditions on low-energy fluctuations that allow for a positive CC despite a negative string-scale CC.
• To determine whether the swampland conjecture remains relevant when quantum effects are included in the effective field theory framework.

Proposed method

• Analyzing the effective field theory of type IIB string compactifications in the large volume scenario with a negative cosmological constant.
• Evaluating one-loop radiative corrections to the scalar potential below the Kaluza-Klein scale.
• Applying conditions on the spectrum of light modes (e.g., mass gaps and couplings) to determine whether the corrections can lift the vacuum energy to positive values.
• Using supersymmetry breaking minima in the large volume limit to compute the quantum corrections' net effect on the cosmological constant.
• Assessing the stability and consistency of the resulting vacuum with a positive CC under the specified spectral constraints.
• Comparing the quantum-corrected vacuum energy to the original string-theoretic CC to determine the net sign of the cosmological constant.

Experimental results

Research questions

• RQ1 Can radiative corrections in the large volume scenario of type IIB string theory generate a positive cosmological constant despite a negative string-scale CC?
• RQ2 What specific conditions on the low-energy spectrum are required for the radiative correction to produce a positive CC?
• RQ3 Under what circumstances does the de Sitter swampland conjecture lose its physical relevance in this quantum-corrected framework?
• RQ4 How do quantum corrections below the Kaluza-Klein scale affect the stability of the supersymmetry-breaking minimum with negative CC?
• RQ5 Is the observed positive CC in the effective theory consistent with the underlying string theory landscape?

Key findings

• Radiative corrections below the Kaluza-Klein scale can generate a positive cosmological constant even when the string-theoretic CC is negative.
• The generation of a positive CC depends on mild conditions being satisfied by the spectrum of low-energy fluctuations, particularly regarding mass gaps and couplings.
• The resulting vacuum with a positive CC is consistent with the effective field theory framework of the large volume scenario.
• The de Sitter swampland conjecture, while possibly valid at high scales, may not constrain viable low-energy vacua if quantum corrections can naturally produce de Sitter-like behavior.
• The mechanism operates within the known landscape of type IIB compactifications without requiring new physics beyond standard quantum corrections.
• The net cosmological constant after corrections can be positive if the low-energy spectrum supports sufficient positive contributions from loop diagrams.