Hilbert-Kunz multiplicity of powers of an ideal III

Người báo cáo: Jugal Verma (Indian Institute of Technology, Mumbai)

Time: 9:00 -- 10:15, December 18, 2024

Venue: Room 612, A6, Institute of Mathematics-VAST

Abstract: Let (R,mathfrakm) be a d-dimensional local ring, I be an mathfrakm-primary ideal and let R have prime characteristic p.
K.-I. Watanabe and K.-I. Yoshida investigated the Hilbert-Kunz multiplicity of powers of I in terms of Hilbert coefficients of I and its Frobenius powers I[q] where q=pn. It was proved by V. Trivedi that if I is zero-dimensional graded ideal of a standard graded ring R of dimension d over a field, then L1(I)=limqtoinftye1(I[q])/qd exists. Illya Smirnov proved Trivedi's result for mathfrakm-primary ideals of all local rings. Smirnov asked if Lk(I)=limqtoinftyek(I[q])/qd exists for k=2,3,ldots,d and whether the HK multiplicity of In for all large n is given by the formula [e_{HK}(I^n)=sum_{k=0}^d (-1)^k L_k(I)binom{n+d-k-1}{d-k}.] Smirnov also conjectured that ideals of reduction number one can be characterised in terms of the HK multiplicity. I will report on joint works with {bf Kriti Goel, Arindam Banerjee and Shreedevi Masuti, Marilina Rossi and Alessandro De Stefani, } which provide partial answers to Smirnov's questions.