2003/06/30 by Zhi-Wei Sun
Mathematics · #math.GR #math.NT #msc:20D60 #msc:05A18 #msc:11B25 #msc:11N45 #msc:20D20 #msc:20D35 #msc:20E15 #msc:20F16
published as J. Algebra 273(2004), no. 1, 153--175 · 22 pages
arxiv created 2004/12/30 · arxiv updated 2009/11/30
Let G be any group and a1G1,...,akGk (k>1) be left cosets in G. In 1974 Herzog and Schönheim conjectured that if \Cal A=\aiGi\i=1k is a partition of G then the (finite) indices n1=[G:G1],...,nk=[G:Gk] cannot be distinct. In this paper we show that if \Cal A covers all the elements of G the same times and G1,...,Gk are subnormal subgroups of G not all equal to G, then M=max1≤ j≤ k|\1≤ i≤ k:ni=nj\| is not less than the smallest prime divisor of n1... nk, moreover min1\ls i\ls klog ni=O(Mlog2 M) where the O-constant is absolute.