2019/09/30 by Arthur Hebecker, Torben Skrzypek, Manuel Wittner · 1 citation
Physics and Astronomy · #hep-th #gr-qc
paper · pdf · doi:10.1007/jhep11(2019)134
published as JHEP 1911:134,2019 · 24 pages; v2: comment and references added
arxiv created 2020/02/24 · arxiv updated 2020/02/26
We attempt a systematic analysis of string-theoretic quintessence models as an alternative to metastable de Sitter vacua. It appears that, within the boundaries of what is known, large-volume type-IIB flux compactifications are preferred. Here the quintessence scalar is the ratio of certain 4-cycle volumes. It has already been noticed that the volume modulus, which must be stabilized, tends to remain too light. One may call this the "light volume problem". In addition, we identify an "F-term problem": The positive energy density of standard-model SUSY breaking is higher than the depth of all known negative contributions. We discuss what it would take to resolve these issues and comment on partially related challenges for axionic quintessence. In particular, large cancellations between positive and negative potential terms appear unavoidable in general. As a further challenge, one should then explain why a small de-tuning cannot be used to uplift into a deep slow-roll regime, violating de Sitter swampland conjectures.