On monomial ideals and their socles

TL;DR

This paper provides a constructive method to determine monomial ideals with prescribed socle monomials using lattice structures, duality, and characterizes certain zero-dimensional ideals of specific types.

Contribution

It introduces a lattice-based construction for monomial ideals with specified socles, explores duality between upsets and downsets, and characterizes zero-dimensional ideals of type k.

Findings

Constructive method for monomial ideals with given socle monomials.

Duality results between upsets and downsets in ^d.

Characterization of zero-dimensional ideals of type k.

Abstract

For a finite subset $M\subset [x_1,\ldots,x_d]$ of monomials, we describe how to constructively obtain a monomial ideal $I\subseteq R = K[x_1,\ldots,x_d]$ such that the set of monomials in $\text{Soc}(I)\setminus I$ is precisely $M$, or such that $\overline{M}\subseteq R/I$ is a $K$-basis for the the socle of $R/I$. For a given $M$ we obtain a natural class of monomials $I$ with this property. This is done by using solely the lattice structure of the monoid $[x_1,\ldots,x_d]$. We then present some duality results by using anti-isomorphisms between upsets and downsets of $(\mathbb Z^d,\preceq)$. Finally, we define and analyze zero-dimensional monomial ideals of $R$ of type $k$, where type $1$ are exactly the Artinian Gorenstein ideals, and describe the structure of such ideals that correspond to order-generic antichains in $\mathbb Z^d$.