Gauge R-symmetry and de Sitter vacua in supergravity and string theory

A new class of metastable de Sitter vacua is presented and analyzed in N=1 supergravity and string theory with tunable (infinitesimally small) value of the cosmological constant. They are based on a gauged R-symmetry and the minimal spectrum contains a vector and a linear multiplet of the string dilaton or of a compactification modulus. In the minimum of the scalar potential supersymmetry is broken by an expectation value of both a D- and F-term