How a four-dimensional de Sitter solution remains outside the swampland

We argue that, in the presence of time-dependent fluxes and quantum corrections, four-dimensional de Sitter solutions should appear in the type IIB string landscape and not in the swampland. Our construction considers generic choices of local and non-local quantum terms and satisfies the no-go and the swampland criteria, the latter being recently upgraded using the trans-Planckian cosmic censorship. Interestingly, both time-independent Newton constant and moduli stabilization may be achieved in such backgrounds even in the presence of time-dependent fluxes and internal spaces. However, once the time-dependence is switched off, any four-dimensional solution with de Sitter isometries appears to have no simple effective field theory descriptions and is back in the swampland.

Automated summary

The article discusses the possibility of four-dimensional de Sitter solutions appearing in the IIB string landscape in the presence of time-dependent fluxes and quantum corrections, while achieving time-independent Newton constant and moduli stabilization. However, once the time-dependence is removed, solutions with de Sitter isometries seem to lack a simple effective field theory description and fall back into the swampland.