本刊英文版Vol.27(2011),No.11论文摘要

<正>For a bipartite graph G on m and n vertices,respectively,in its vertices classes, and for integers s and t such that 2≤s≤t,0≤m-s≤n-t,and m+n≤2s+t-1,we prove that if G has at least mn -(2(m - s) + n - t) edges then it contains a subdivision of the complete bipartite K_((s,t)) with s vertices in the m-class and t vertices in the n-class.Furthermore, we characterize the corresponding extremal bipartite graphs with mn -(2(m - s) + n - t + 1) edges for this topological Turan type problem.