%0 PDF %T Noncommutators and the number of projective characters of a finite group. %A Reynolds, William F. %D 2018-07-19T09:44:23.953-04:00 %8 2018-07-19 %I Tufts University. Tisch Library. %R http://localhost/files/rv043526q %X Let ƒ be a 2-cocycle of a finite group G over the multiplicative group of the complex field with trivial action. Schur already knew that the number of irreducible projective characters of G in C for ƒ (or ƒ-characters for short) is less than or equal to the number of conjugacy classes of G. No one seems to have asked whether it is possible to have equality when ƒ is not a coboundary. We show that this can indeed happen, give a simple criterion for it, and discuss some examples. First published in Proceedings of Symposia in Pure Mathematics in volume 47.2, published by the American Mathematical Society. %[ 2018-10-10 %9 Text %~ Tufts Digital Library %W Institution