One-loop bosonic string and De Sitter space
arXiv:1810.02236 · doi:10.1016/j.nuclphysb.2019.114768
Abstract
We calculate the bosonic string one-loop three- and four-point amplitudes to quadradic order in momentum, and we read off the one-loop low-energy two-derivative effective action for the massless fields, . Treating the renormalized one-loop vacuum energy as a tunable parameter and extrapolating to a supercritical dimension , one can reach a regime where the one-loop couplings in Seff are of the same order as the tree-level ones while all higher-loop corrections are negligible. Moreover the effective spacetime curvature is small in string units. We show that the effective action thus obtained admits weakly-curved de Sitter solutions with constant dilaton at small string coupling.
40 pages. v2: conclusions section extended, published version