2014/03/31 by Dipankar Ghosh, Tony J. Puthenpurakal · 1 citation
Mathematics · #math.AC #msc:13A02 #msc:13A15 #msc:13D07 #msc:13H10
paper · pdf · doi:10.1017/s0305004115000778
published as Math. Proc. Camb. Phil. Soc. 160 (2016) 423-436 · 17 pages, final version
arxiv created 2016/11/11 · arxiv updated 2016/11/14
Let A be a local complete intersection ring. Let M,N be two finitely generated A-modules and I an ideal of A. We prove that \bigcupi\geqslant 0\bigcupn \geqslant 0AssA(ExtAi(M,N/In N)) is a finite set. Moreover, we prove that there exist i0,n0\geqslant 0 such that for all i\geqslant i0 and n \geqslant n0, we have AssA(ExtA2i(M,N/InN)) = AssA(ExtA2 i0(M,N/In0N)), AssA(ExtA2i+1(M,N/InN)) = AssA(ExtA2 i0 + 1(M,N/In0N)). We also prove the analogous results for complete intersection rings which arise in algebraic geometry. Further, we prove that the complexity cxA(M,N/InN) is constant for all sufficiently large n.