The Irish ‘Decade of Centenaries’ is, at last, drawing to a close, ending the ‘interminable round national soul-searching’ which one prominent historian warily anticipated in 2013. 1 final major event be commemorated is Civil War 1922–3, when republican movement split bitterly and violently over terms treaty granting southern part Ireland partial independence from Britain. As it turns out, gove...

Later in 1957, as the end of my three-year tour of duty in the Navy was approaching, Princeton invited me to return as Higgins Lecturer in Mathematics. I had been a Williams undergraduate and a then a graduate student at Cambridge and Princeton while getting my Ph.D. I had published 4 papers in non-linear differential equations, a subject to which I had been introduced by two wonderful people w...

We intend to provide an algebraic framework in which some of the algebraic theory of connections become identical to some of the (Eilenberg Mac Lane) theory of extensions of non-abelian groups. In particular, the Bianchi identity for the curvature of a connection is related to one of the crucial equations in extension theory. The Bianchi identity as a purely combinatorial fact was dealt with in...