The landscape, the swampland and the era of precision cosmology
  We review the advanced version of the KKLT construction and pure $d=4$ de
Sitter supergravity, involving a nilpotent multiplet, with regard to various
conjectures that de Sitter state cannot exist in string theory. We explain why
we consider these conjectures problematic and not well motivated, and why the
recently proposed alternative string theory models of dark energy, ignoring
vacuum stabilization, are ruled out by cosmological observations at least at
the $3\sigma$ level, i.e. with more than $99.7\%$ confidence.
