On Lech’s limit formula for modules
Tom 148 / 2017
Streszczenie
Let $R=\bigoplus _{n=0}^{\infty } R_n$ be a standard graded algebra and $M=\bigoplus _{n=0}^{\infty } M_n$ a graded Noetherian $R$-module. The main objective of this work is to derive a Lech type formula for a sequence of homogeneous elements $a_1,\dots ,a_m$ of degree one which form a $g$-multiplicity system of $R$. We also extend to this context the well known Serre Theorem, that is, we prove that for $t\gg 0$ the $g$-multiplicity symbol $e_t(a_1,\dots ,a_m;R)$, introduced by Kirby (1987), coincides with the Buchsbaum–Rim multiplicity $e_{\rm BR}(I;R)$ of the $R_0$-module $I$ generated by $a_1,\dots ,a_m.$