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Let $T$ be a perfect binary tree and $I$ be its edge ideal in the polynomial ring $S$. We determine the vertex cover number, independent number, and establish the recursive formula to compute the number of minimal vertex covers. As a…

Commutative Algebra · Mathematics 2025-09-25 Nguyen Thu Hang , Tran Duc Dung , Do Van Kien

For an ideal $I$ in a regular local ring or a graded ideal $I$ in the polynomial ring we study the limiting behavior of the Betti numbers of S/I^k as k goes to infinity. By Kodiyalam's result it is known that in each homological degree the…

Commutative Algebra · Mathematics 2009-10-20 Juergen Herzog , Volkmar Welker

We characterize componentwise linear monomial ideals with minimal Taylor resolution and consider the lower bound for the Betti numbers of componentwise linear ideals.

Commutative Algebra · Mathematics 2007-05-23 Juergen Herzog , Takayuki Hibi , Satoshi Murai , Yukihide Takayama

Let I be a homogeneous ideal in a polynomial ring P over a field. By Macaulay's Theorem, there exists a lexicographic ideal L=Lex(I) with the same Hilbert function as I. Peeva has proved that the Betti numbers of P/I can be obtained from…

Commutative Algebra · Mathematics 2009-04-08 Maria Evelina Rossi , Leila Sharifan

In the present paper, we characterize all possible Hilbert functions of graded ideals in a polynomial ring whose regularity is smaller than or equal to $d$, where $d$ is a positive integer. In addition, we prove the following result which…

Commutative Algebra · Mathematics 2007-06-26 Satoshi Murai

In this expositional paper, we discuss commutative algebra -- a study inspired by the properties of integers, rational numbers, and real numbers. In particular, we investigate rings and ideals, and their various properties. After, we…

Algebraic Geometry · Mathematics 2021-10-19 Marc Maliar

Let S be a polynomial ring in n variables, over an arbitrary field. We give the total, graded, and multigraded Betti numbers of S/M, for every monomial ideal M in S. We also give an explicit characterization of all monomial ideals M in S…

Commutative Algebra · Mathematics 2017-10-17 Guillermo Alesandroni

Let $K$ be a field and $S = K[x_1,\dots,x_n]$ be a polynomial ring over $K$. We discuss the behaviour of the extremal Betti numbers of the class of squarefree strongly stable ideals. More precisely, we give a numerical characterization of…

Commutative Algebra · Mathematics 2021-10-01 Luca Amata , Marilena Crupi

We investigate properties of zeta functions of polynomial rings and their quotients, generalizing and extending some classical results about Dedekind zeta functions of number fields. By an application of Delange's version of the Ikehara…

Number Theory · Mathematics 2017-01-18 Lenny Fukshansky , Stefan Kühnlein , Rebecca Schwerdt

We introduce and study the mixed Segre zeta function of a sequence of homogeneous ideals in a polynomial ring. This function is a power series encoding information about the mixed Segre classes obtained by extending the ideals to projective…

Algebraic Geometry · Mathematics 2025-07-10 Yairon Cid-Ruiz

We investigate the structure and properties of symmetric ideals generated by general forms in the polynomial ring under the natural action of the symmetric group. This work significantly broadens the framework established in our earlier…

Commutative Algebra · Mathematics 2025-06-19 Alexandra Seceleanu , Liana Şega

We introduce and study monomial ideals with regular quotients, which can be seen as an extension of monomial ideals with linear quotients. Based on these investigations, we are able to calculate the Betti numbers of toric ideals belonging…

Commutative Algebra · Mathematics 2023-08-08 Dancheng Lu , Hao Zhou

In this paper we study the class of power ideals generated by the $k^n$ forms $(x_0+\xi^{g_1}x_1+\ldots+\xi^{g_n}x_n)^{(k-1)d}$ where $\xi$ is a fixed primitive $k^{th}$-root of unity and $0\leq g_j\leq k-1$ for all $j$. For $k=2$, by using…

Commutative Algebra · Mathematics 2018-12-13 Jörgen Backelin , Alessandro Oneto

Let $\Delta$ be a stable simplicial complex on $n$ vertexes. Over an arbitrary base field $K$, the symmetric algebraic shifted complex $\Delta^s$ of $\Delta$ is defined. It is proved that the Betti numbers of the Stanley-Reisner ideals in…

Commutative Algebra · Mathematics 2007-05-23 Zhongming Tang , Guifen Zhuang

Let $R=\Bbbk[x_1,\dots,x_n]$ be a polynomial ring over a field $\Bbbk$ and let $I\subset R$ be a monomial ideal preserved by the natural action of the symmetric group $\mathfrak S_n$ on $R$. We give a combinatorial method to determine the…

Commutative Algebra · Mathematics 2022-03-09 Satoshi Murai , Claudiu Raicu

We define a power series associated with a homogeneous ideal in a polynomial ring, encoding information on the Segre classes defined by extensions of the ideal in projective spaces of arbitrarily high dimension. We prove that this power…

Algebraic Geometry · Mathematics 2018-01-25 Paolo Aluffi

An ideal of polynomials is symmetric if it is closed under permutations of variables. We relate general symmetric ideals to the so called Specht ideals generated by all Specht polynomials of a given shape. We show a connection between the…

Algebraic Geometry · Mathematics 2021-02-17 Philippe Moustrou , Cordian Riener , Hugues Verdure

Let $G$ be a cycle or a complete bipartite graph. We show that the binomial edge ideal $J_{G}$ and its initial ideal with respect to the lexicographic order have the same extremal Betti number.

Commutative Algebra · Mathematics 2013-10-11 Ahmet Dokuyucu

Given an ideal of forms in an algebra (polynomial ring, tensor algebra, exterior algebra, Lie algebra, bigraded polynomial ring), we consider the Hilbert series of the factor ring. We concentrate on the minimal Hilbert series, which is…

Commutative Algebra · Mathematics 2018-11-19 Ralf Fröberg , Samuel Lundqvist

We express the multigraded Betti numbers of monomial ideals in 4 variables in terms of the multigraded Betti numbers of 66 squarefree monomial ideals, also in 4 variables. We use this class of 66 ideals to prove that monomial resolutions in…

Commutative Algebra · Mathematics 2019-05-06 Guillermo Alesandroni