Naturally reductive reducible \(R\Sigma\)-spaces (Q1916554)

By using [\textit{A. J. Ledger} and \textit{A. R. Razavi}, Ill. J. Math. 26, 272-292 (1982; Zbl 0495.53047)], an important class of reducible \(\Sigma\)-spaces with compact group \(\Sigma\) is studied here, namely the class consisting of reducible Riemannian \(\Sigma\)-spaces whose Riemannian connection is the canonical connection of the first genus. They are called naturally reductive reducible \(R\Sigma\)-spaces. A description of the structure of these spaces of compact type and the complete list of them in the case of simple spaces of noncompact type are given here.