Nowhere zero flow and circuit covering in regular matroids (Q1070235)

This paper deals with circuit coverings of regular matroids. Denoting by s(k) the smallest s such that, if there is a k-nowhere zero flow in the regular matroid M, then M can be covered by circuits the total length of which is at most \(s| M|\). The main result of the paper is a recursive formula for the evaluation of s(k), namely \(s(kt)\leq (s(k)(kt- t)+s(t)(kt-k))/(kt-1),\) for k,t\(\geq 2\).