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Related papers: Theta-regularity and log-canonical threshold

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We discuss the behavior of the Castelnuovo-Mumford regularity under certain operations on ideals and modules, like products or powers. In particular, we show that reg(IM) can be larger than reg(M)+reg(I) even when I is an ideal of linear…

Commutative Algebra · Mathematics 2007-05-23 Aldo Conca , Juergen Herzog

We consider pairs (X,A), where X is a variety with klt singularities and A is a formal product of ideals on X with exponents in a fixed set that satisfies the Descending Chain Condition. We also assume that X has (formally) bounded…

Algebraic Geometry · Mathematics 2010-06-25 Tommaso de Fernex , Lawrence Ein , Mircea Mustata

We prove new incidence bounds between a plane point set, which is a Cartesian product, and a set of translates $H$ of the hyperbola $xy=\lambda\neq 0$, over a field of asymptotically large positive characteristic $p$. They improve recent…

Combinatorics · Mathematics 2021-04-22 Misha Rudnev , James Wheeler

We compute the Castelnuovo-Mumford regularity of the edge ideals of two families of circulant graphs, which includes all cubic circulant graphs. A feature of our approach is to combine bounds on the regularity, the projective dimension, and…

Commutative Algebra · Mathematics 2019-07-24 Miguel Eduardo Uribe-Paczka , Adam Van Tuyl

We use Toponogov's triangle comparison theorem from Riemannian geometry along with quantitative scale oriented variants of classical propagation of singularities arguments to obtain logarithmic improvements of the Kakeya-Nikodym norms…

Analysis of PDEs · Mathematics 2015-10-29 Matthew D. Blair , Christopher D. Sogge

We present a new method to bound the cardinality of triple product sets in groups and give three applications. A new and unexpectedly short proof of the Plunnecke-Ruzsa sumset inequalities for Abelian groups. A new proof of a theorem of Tao…

Combinatorics · Mathematics 2013-09-10 Giorgis Petridis

Multigraded Castelnuovo--Mumford regularity of a module $M$ over the total coordinate ring $S$ of a smooth projective toric variety $X$ is a region $\operatorname{reg} M \subset \operatorname{Pic} X$ invariant under translation by the nef…

Commutative Algebra · Mathematics 2025-03-03 Juliette Bruce , Lauren Cranton Heller , Mahrud Sayrafi

Let $\varphi$ be a plurisubharmonic function defined in a neighborhood of the origin in $\mathbb C^n$. For each real number $t>-n$, we associate to $\varphi$ the weighted log canonical threshold \[ c_t(\varphi):=\sup\Bigl\{c\geq…

Complex Variables · Mathematics 2026-02-13 Nguyen Xuan Hong

When M is a finitely generated graded module over a standard graded algebra S and I is an ideal of S, it is known from work of Cutkosky, Herzog, Kodiyalam, R\"omer, Trung and Wang that the Castelnuovo-Mumford regularity of I^mM has the form…

Commutative Algebra · Mathematics 2010-12-07 David Eisenbud , Bernd Ulrich

We derive new bounds for the Castelnuovo-Mumford regularity of the ideal sheaf of a complex projective manifold of any dimension. They depend linearly on the coefficients of the Hilbert polynomial, and are optimal for rational scrolls, but…

Algebraic Geometry · Mathematics 2020-03-12 Juergen Rathmann

Using log canonical thresholds and basis divisors Fujita--Odaka introduced purely algebro-geometric invariants $\delta_m$ whose limit in $m$ is now known to characterize uniform K-stability on a Fano variety. As shown by Blum-Jonsson this…

Differential Geometry · Mathematics 2024-11-20 Yanir A. Rubinstein , Gang Tian , Kewei Zhang

A multilateral Bailey Lemma is proved, and multiple analogues of the Rogers--Ramanujan identities and Euler's Pentagonal Theorem are constructed as applications. The extreme cases of the Andrews--Gordon identities are also generalized using…

Combinatorics · Mathematics 2010-02-02 Hasan Coskun

We generalize the rationality theorem of the accumulation points of log canonical thresholds which was proved by Hacon, M\textsuperscript{c}Kernan, and Xu. Further, we apply the rationality to the ACC problem on the minimal log…

Algebraic Geometry · Mathematics 2024-04-30 Yusuke Nakamura

We study the Castelnuovo-Mumford regularity of powers of edge ideals. We prove that if G is a bipartite graph, then reg(I(G)^s) \leq 2s + reg I(G) - 2 for all s \geq 2, which is the best possible upper bound for any s. Suspension plays a…

Commutative Algebra · Mathematics 2019-09-06 Arindam Banerjee , Eran Nevo

We apply Angehrn-Siu-Helmke's method to estimate basepoint freeness thresholds of higher dimensional polarized abelian varieties. We showed that a conjecture of Caucci holds for very general polarized abelian varieties in the moduli spaces…

Algebraic Geometry · Mathematics 2022-07-12 Zhi Jiang

For a scheme of fat points $Z$ defined by the saturated ideal $\mathcal{I}_Z$, the regularity index computes the Castelnuovo-Mumford regularity of the Cohen-Macaulay ring $R/\mathcal{I}_Z.$ For points in " general position" we improve the…

Algebraic Geometry · Mathematics 2015-10-27 Edoardo Ballico , Olivia Dumitrescu , Elisa Postinghel

Bounds for the Castelnuovo-Mumford regularity of Ext modules, over a polynomial ring over a field, are given in terms of the initial degrees, Castelnuovo-Mumford regularities and number of generators of the two graded modules involved.…

Commutative Algebra · Mathematics 2009-03-27 Marc Chardin , Dao Thanh Ha , Le Tuan Hoa

Let $(A,\Theta)$ be a principally polarised abelian variety, and let Y be a subvariety. Pareschi and Popa conjectured that Y has minimal cohomology class if and only if the structure sheaf of Y satisfies a property that they call…

Algebraic Geometry · Mathematics 2017-12-19 Andreas Höring

For a class of systems of semi-linear elliptic equations, including \[ -\Delta u_i=f_i(x,u_i) - \beta u_i\sum_{j\neq i}a_{ij}u_j^p,\qquad i=1,\dots,k, \] for $p=2$ (variational-type interaction) or $p = 1$ (symmetric-type interaction), we…

Analysis of PDEs · Mathematics 2016-10-26 Nicola Soave , Alessandro Zilio

In this paper we prove the conjectured upper bound for Castelnuovo-Mumford regularity of binomial edge ideals posed in [23], in the case of chordal graphs. Indeed, we show that the regularity of any chordal graph G is bounded above by the…

Commutative Algebra · Mathematics 2018-10-09 M. Rouzbahani Malayeri , S. Saeedi Madani , D. Kiani
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