‎let $i$ denote an ideal of a noetherian ring $r$‎. ‎the purpose of‎ ‎this article is to introduce the concepts of quintasymptotic‎ ‎sequences over $i$ and quintasymptotic cograde of $i$‎, ‎and to show that they play a role analogous to quintessential sequences‎ ‎over $i$ and quintessential cograde of $i$‎. ‎we show that‎, ‎if $r$ is‎ ‎local‎, ‎then the quintasymptotic cograde of $i$ is una...

Weak Bourbaki unmixed rings are defined in this paper. The definition of a weak Bourbaki unmixed ring is a candidate for an “appropriate” definition of CohenMacaulayness. We will see that this definition satisfies many of the conditions we want an “appropriate” definition to satisfy. It is not yet known whether this definition (or any other) satisfies all of the conditions. However, no example ...

A result of Watanabe and Yoshida says that an unmixed local ring of positive characteristic is regular if and only if its Hilbert-Kunz multiplicity is one. We show that, for fixed p and d, there exist a number ǫ(d, p) > 0 such that any nonregular unmixed ring R its Hilbert-Kunz multiplicity is at least 1+ ǫ(d, p). We also show that local rings with sufficiently small Hilbert-Kunz multiplicity a...

In a paper in 2008, Herzog, Hibi and Ohsugi introduced and studied the semigroup ring associated to the set of minimal vertex covers of an unmixed bipartite graph. In this paper we relate the dimension of this semigroup ring to the rank of the Boolean lattice associated to the graph.

In a paper in 2008, Herzog, Hibi and Ohsugi introduced and studied the semigroup ring associated to the set of minimal vertex covers of an unmixed bipartite graph. In this paper we relate the dimension of this semigroup ring to the rank of the Boolean lattice associated to the graph.

Let R be a polynomial ring over a field in an unspecified number of variables. We prove that if J ⊂ R is an ideal generated by three cubic forms, and the unmixed part of J contains a quadric, then the projective dimension of R/J is at most 4. To this end, we show that if K ⊂ R is a three-generated ideal of height two and L ⊂ R an ideal linked to the unmixed part of K, then the projective dimens...

This paper considers the following conjecture: If R is an unmixed, equidimensional local ring that is a homomorphic image of a Cohen-Macaulay local ring, then for any ideal J generated by a system of parameters, the Chern coefficient e1(J) < 0 is equivalent to R being non Cohen-Macaulay. The conjecture is established if R is a homomorphic image of a Gorenstein ring, and for all universally cate...

We settle the negativity conjecture of Vasconcelos for the Chern number of an ideal in certain unmixed quotients of regular local rings by explicit calculation of the Hilbert polynomials of all ideals generated by systems of parameters. Introduction Let I be an m-primary ideal in a local ring (R,m) of dimension d. Let H(I, n) = λ(R/I) denote the Hilbert function of I where λ(M) denotes the leng...

An equigenerated monomial ideal $$I$$ in the polynomial ring $$R=k[z_1,\ldots, z_n]$$ is a Freiman if $$\mu(I^2)=\ell(I)\mu(I)-{\ell(I)\choose 2}$$ , where $$\ell(I)$$ analytic spread of and $$\mu(I)$$ number minimal generators . In this paper we classify all simple connected unmixed bipartite graphs whose cover ideals are ideals.

In this paper, an algebraic theory for local rings of finite embedding dimension is developed. Several extensions of (Krull) dimension are proposed, which are then used to generalize singularity notions from commutative algebra. Finally, variants of the homological theorems are shown to hold in equal characteristic. This theory is then applied to Noetherian local rings in order to get: (i) over...