Published in Illinois Journal of Mathematics, Volume 38, January 1, 1994, pages 679-691.
NOTE: At the time of publication, the author Joseph E. Borzellino was not yet affiliated with Cal Poly.
In this paper we wish to examine a generalization of the splitting theorem of Cheeger–Gromoll [CG] to Riemannian orbifolds. Roughly speaking, a Riemannian orbifold is a metric space locally modelled on quotients of Rie- mannian manifolds by finite groups of isometries. The term orbifold was coined by W. Thurston [T] sometime around the year 1976–77. The term is meant to suggest the orbit space of a group action on a manifold. A similar concept was introduced by I. Satake in 1956, where he used the term V–manifold (See [S1]). The “V” was meant to suggest a cone–like singularity. Since then, orbifold has become the preferred terminology.
1994 Board of Trustees of the University of Illinois.