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Related papers: Segre's Regularity Bound for Fat Point Schemes

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The local theory of regular or multi-regular systems aims at finding sufficient local conditions for a Delone set $X$ to be a regular or multi-regular system. One of the main goals is to estimate the regularity radius $\hat{\rho}_d$ for…

Currently, the best upper bounds on the number of rational points on an absolutely irreducible, smooth, projective algebraic curve of genus g defined over a finite field F_q come either from Serre's refinement of the Weil bound if the genus…

Algebraic Geometry · Mathematics 2007-05-23 Kristin Lauter , Jean-Pierre Serre

Let $S$ be a polynomial ring in $n$ variables over a field. Let $I$ be a homogeneous ideal in $S$ generated by forms of degree at most $d$ with $\text{dim}(S/I)=r$. In the first part of this paper, we show how to derive from a result of Hoa…

Commutative Algebra · Mathematics 2022-04-20 Yihui Liang

Let $\mathcal{D}$ be a weighted oriented graph and let $I(\mathcal{D})$ be its edge ideal in a polynomial ring $R$. We give the formula of Castelnuovo-Mumford regularity of $R/I(\mathcal{D})$ when $\mathcal{D}$ is a weighted oriented path…

Commutative Algebra · Mathematics 2022-09-23 Selvi Kara , Jennifer Biermann , Kuei-Nuan Lin , Augustine O'Keefe

For a smooth $k$-dimensional submanifold $\Sigma$ of a $d$-dimensional compact Riemannian manifold $M$, we extend the $L^p(\Sigma)$ restriction bounds of Burq-G\'erard-Tzvetkov -- originally proved for individual Laplace--Beltrami…

Analysis of PDEs · Mathematics 2025-05-28 Changbiao Jian , Xing Wang , Yakun Xi

This paper is concerned with determining the number of generators in each degree for minimal sets of homogeneous generators for saturated ideals defining fat point subschemes $Z=m_1p_1+ ... +m_rp_r$ for general sets of points $p_i$ of…

alg-geom · Mathematics 2008-02-03 Brian Harbourne

In this note, pointwise best-possible (lower and upper) bounds on the set of copulas with a given value of the Gini's gamma coefficient are established. It is shown that, unlike the best-possible bounds on the set of copulas with a given…

Statistics Theory · Mathematics 2025-01-14 Manuel Úbeda-Flores

There are two motivation questions in \cite{MTS, MTS1} about Castelnuovo-Mumford regularity and vertex decomposable of simple graph $G$. In this paper, we disprove the questions by providing of two counterexamples.

Combinatorics · Mathematics 2022-11-24 Amir Mafi , Dler Naderi , Parasto Soufivand

We present two new problems on lower bounds for resolution Betti numbers of monomial ideals generated in a fixed degree. The first concerns any such ideal and bounds the total Betti numbers, while the second concerns ideals that are…

Commutative Algebra · Mathematics 2007-12-18 Uwe Nagel , Victor Reiner

We consider the open problem of determining the graded Betti numbers for fat point subschemes supported at general points of the projective plane. We relate this problem to the open geometric problem of determining the splitting type of the…

Algebraic Geometry · Mathematics 2007-06-19 Alessandro Gimigliano , Brian Harbourne , Monica Idà

Let $\mathrm{rex}(n, F)$ denote the maximum number of edges in an $n$-vertex graph that is regular and does not contain $F$ as a subgraph. We give lower bounds on $\mathrm{rex}(n, F)$, that are best possible up to a constant factor, when…

Combinatorics · Mathematics 2020-05-27 Michael Tait , Craig Timmons

In this paper we study ideals of points lying on rational normal curves defined in projective plane and projective $ 3 $-space. We give an explicit formula for the value of Castelnuovo-Mumford regularity for their ordinary powers. Moreover,…

Algebraic Geometry · Mathematics 2020-07-20 Iman Bahmani Jafarloo , Grzegorz Malara

The present work is concerned with characterizing some algebraic invariants of edge ideals of hypergraphs. To this aim, firstly, we introduce some kinds of combinatorial invariants similar to matching numbers for hypergraphs. Then we…

Commutative Algebra · Mathematics 2025-06-10 Somayeh Moradi , Fahimeh Khosh-Ahang Ghasr

In this paper we give upper bounds for the regularity of edge ideal of some classes of graphs in terms of invariants of graph. We introduce two numbers $a'(G)$ and $n(G)$ depending on graph $G$ and show that for a vertex decomposable graph…

Commutative Algebra · Mathematics 2016-01-05 Somayeh Moradi , Dariush Kiani

We study the higher regularity of free boundaries in obstacle problems for integro-differential operators. Our main result establishes that, once free boundaries are $C^{1,\alpha}$, then they are $C^\infty$. This completes the study of…

Analysis of PDEs · Mathematics 2019-12-16 Nicola Abatangelo , Xavier Ros-Oton

In this paper we consider a generalization of a well known result by Veronese about rational normal curves. More precisely, given a collection of linear spaces in $\PP^n$ we study the existence of rational normal curves intersecting each…

Algebraic Geometry · Mathematics 2014-02-26 E. Carlini , M. V. Catalisano

Robust subsets of matroids were introduced by Huang and Sellier to propose approximate kernels for the matroid-constrained maximum vertex cover problem. In this paper, we prove that the bound for robust subsets of transversal matroids given…

Combinatorics · Mathematics 2022-10-19 Naoyuki Kamiyama

We obtain optimal lower bounds for moments of theta functions. On the other hand, we also get new upper bounds on individual theta values and moments of theta functions on average over primes. The upper bounds are based on bounds of…

Number Theory · Mathematics 2015-06-08 Marc Munsch , Igor E. Shparlinski

For any affine hypersurface defined by a complete symmetric polynomial in $k\geq 3$ variables of degree $m$ over the finite field $\mathbb{F}_{q}$ of $q$ elements, a special case of our theorem says that this hypersurface has at least…

Number Theory · Mathematics 2020-07-23 Jun Zhang , Daqing Wan

For, $0<\lambda<1$, consider the transformation $T(x) = d x $ (mod 1) on the circle $S^1$, a $C^1$ function $A:S^1 \to \mathbb{R}$, and, the map $F(x,s) = ( T(x) , \lambda \, s + A(x))$, $(x,s)\in S^1 \times \mathbb{R}$. We denote…

Dynamical Systems · Mathematics 2016-12-16 Artur O. Lopes , Elismar R. Oliveira