Published online by Cambridge University Press: 24 October 2008
Let Bn denote the Artin braid group on ‘n-strings[ and PBn its normal subgroup consisting of all the pure braids [Bi, Mo]. These groups have been considerably scrutinized by both topologists and algebraists [BL]. One question whose answer has so far eluded us is whether or not the Gassner representation G: PBn → Mn × n(λ), into the group of n-by-n matrices over , is faithful (see Section 1) [Bi; ·3] [Ga]. Recently the less discriminating Burau representation B: PBn → Mn × n(Z[t±1] ) was shown to have a non-trivial kernel for each n ≥ 6 [M, LP] but these techniques have not yet yielded an element of kernel(G). This paper is a partial step in that direction.