Swampland Conjectures and Late-Time Cosmology
  We discuss the cosmological implications of the string swampland conjectures
for late-time cosmology, and test them against a wide range of state of the art
cosmological observations. The refined de Sitter conjecture constrains either
the minimal slope or the curvature of the scalar potential, and depends on two
dimensionless constants. For constants of size one or larger, tension exists
between observations, especially the Hubble constant, and the slope and
curvature conjectures at a level of 4.5 sigma and 2.3 sigma, respectively.
Smaller values of the constants are permitted by observations, and we determine
upper bounds at varying confidence levels. We also derive and constrain the
relationship between cosmological observables and the scalar field excursion
during the acceleration epoch, thereby testing the distance conjecture.
