The four-dimensional null energy condition as a swampland conjecture
Abstract
We analyze four-dimensional Friedmann-Lemaitre-Robertson-Walker cosmologies in type IIB, arising from a M-theory dual, and find that the null energy condition (NEC) has to be obeyed by them (except for the negatively curved case) in order for the M-theory action to have a Wilsonian effective description. However, this does not imply that the M-theory metric has to obey the 11d NEC. Thus, we propose a new swampland conjecture -- the 4d NEC is a consistency condition for any theory to have a completion within M-theory -- with an explicit derivation of it for cosmological backgrounds from a top-down perspective. We briefly discuss the cosmological consequences of such a condition derived from M-theory.
Cite
@article{arxiv.2107.06900,
title = {The four-dimensional null energy condition as a swampland conjecture},
author = {Heliudson Bernardo and Suddhasattwa Brahma and Keshav Dasgupta and Mir Mehedi Faruk and Radu Tatar},
journal= {arXiv preprint arXiv:2107.06900},
year = {2021}
}
Comments
14 pages (including an Appendix); comments welcome; v2: double-columned 8 pages (includes Supplementary Materials), matches published version