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Fix a square-free monomial $m in S = mathbb{K}[x_1,ldots,x_n]$. The square-free principal Borel ideal generated by $m$, denoted ${rm sfBorel}(m)$, is the ideal generated by all the square-free monomials that can be obtained via Borel moves from the monomial $m$. We give upper and lower bounds for the Waldschmidt constant of ${rm sfBorel}(m)$ in terms of the support of $m$, and in some cases, exact values. For any rational $frac{a}{b} geq 1$, we show that there exists a square-free principal Borel ideal with Waldschmidt constant equal to $frac{a}{b}$.
Fix a poset $Q$ on ${x_1,ldots,x_n}$. A $Q$-Borel monomial ideal $I subseteq mathbb{K}[x_1,ldots,x_n]$ is a monomial ideal whose monomials are closed under the Borel-like moves induced by $Q$. A monomial ideal $I$ is a principal $Q$-Borel ideal, deno
An equigenerated monomial ideal $I$ is a Freiman ideal if $mu(I^2)=ell(I)mu(I)-{ell(I)choose 2}$ where $ell(I)$ is the analytic spread of $I$ and $mu(I)$ is the least number of monomial generators of $I$. Freiman ideals are special since there exists
Let I be a homogeneous ideal of a polynomial ring S. We prove that if the initial ideal J of I, w.r.t. a term order on S, is square-free, then the extremal Betti numbers of S/I and of S/J coincide. In particular, depth(S/I)=depth(S/J) and reg(S/I)=reg(S/J).
We show that the Specht ideal of a two-rowed partition is perfect over an arbitrary field, provided that the characteristic is either zero or bounded below by the size of the second row of the partition, and we show this lower bound is tight. We also
Let $(A,mathfrak{m})$ be an excellent normal domain of dimension two. We define an $mathfrak{m}$-primary ideal $I$ to be a $p_g$-ideal if the Rees algebra $A[It]$ is a Cohen-Macaulay normal domain. When $A$ contains an algebraically closed field $k c