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Related papers: Computing the $F$-pure Threshold of Flag Varieties

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Let $X$ be a smooth hypersurface of degree $n\geq 3$ in $\mathbb{P}^n$. We prove that the log canonical threshold of $H\in|-K_X|$ is at least $\frac{n-1}{n}$. Under the assumption of the Log minimal model program, we also prove that a…

Algebraic Geometry · Mathematics 2007-05-23 Ivan Cheltsov , Jihun Park

Let $X$ be a smooth projective curve defined over an algebraically closed field $k$, and let $E$ be a vector bundle on $X$. We compute the nef cone of any flag bundle associated to $E$.

Algebraic Geometry · Mathematics 2015-11-03 Indranil Biswas , A. J. Parameswaran

Let $k$ be an algebraically closed field of characteristic $p>0$, and let $X\subseteq\mathbb{P}^n_k$ be a quasi-projective variety that is $F$-rational and $F$-pure. We prove that if $H \subseteq \mathbb{P}^n_k$ is a general hyperplane,…

Algebraic Geometry · Mathematics 2025-09-30 Alessandro De Stefani , Thomas Polstra , Austyn Simpson

We introduce and study invariants of singularities in positive characteristic called F-thresholds. They give an analogue of the jumping coefficients of multiplier ideals in characteristic zero. We discuss the connection between the…

Algebraic Geometry · Mathematics 2007-05-23 Mircea Mustata , Shunsuke Takagi , Kei-ichi Watanabe

We investigate the secant dimensions and the identifiablity of flag varieties parametrizing flag of sub vector spaces of a fixed vector space. We give numerical conditions ensuring that secant varieties of flag varieties have the expected…

Algebraic Geometry · Mathematics 2019-12-03 Ageu Barbosa Freire , Alex Casarotti , Alex Massarenti

We introduce conditions on cones of normal toric varieties under which the polyhedron defining the normalized Nash blowup does not depend on the characteristic of the base field. As a consequence, we deduce several results on the resolution…

Algebraic Geometry · Mathematics 2025-01-27 Federico Castillo , Daniel Duarte , Maximiliano Leyton-Álvarez , Alvaro Liendo

We give an explicit formula for the log-canonical threshold of a reduced germ of plane curve. The formula depends only on the first two maximal contact values of the branches and their intersection multiplicities. We also improve the two…

Algebraic Geometry · Mathematics 2016-04-06 C. Galindo , F. Hernando , F. Monserrat

Let G = (V, E) be a finite simple connected graph. We say a graph G realizes a code of the type 0^s_1 1^t_1 0^s_2 1^t_2 ... 0^s_k1^t_k if and only if G can obtained from the code by some rule. Some classes of graphs such as threshold and…

Combinatorics · Mathematics 2022-11-23 Rameez Raja , Samir Ahmad Wagay

In this paper, we prove that the set of all $F$-pure thresholds of ideals with fixed embedding dimension satisfies the ascending chain condition. As a corollary, given an integer $d$, we verify the ascending chain condition for the set of…

Algebraic Geometry · Mathematics 2018-05-21 Kenta Sato

The F-thresholds are characteristic p analogs of the jumping coefficients for multiplier ideals in characteristic zero. In this article we give an alternative description of the F-thresholds of an ideal in a regular and F--finite ring $R$.…

Algebraic Geometry · Mathematics 2011-02-18 Manuel Blickle , Mircea Mustaţǎ , Karen E. Smith

Given a smooth complex algebraic variety $X$ and a nonzero regular function $f$ on $X$, we give an effective estimate for the difference between the jumping numbers of $f$ and the $F$-jumping numbers of a reduction $f_p$ of $f$ to…

Algebraic Geometry · Mathematics 2023-02-08 Mircea Mustaţă

This article describes the \emph{Macaulay2} package \emph{FrobeniusThresholds}, designed to estimate and calculate $F$-pure thresholds, more general $F$-thresholds, and related numerical invariants arising in the study of singularities in…

Commutative Algebra · Mathematics 2021-01-27 Daniel J. Hernández , Karl Schwede , Pedro Teixeira , Emily E. Witt

We develop a new cohomology theory in characteristic p>0, the so called F-gauge cohomology, a cohomology with values in the category of so-called F-gauges, which refines the cristalline cohomology. In this first paper we mainly discuss the…

Algebraic Geometry · Mathematics 2013-04-16 Jean-Marc Fontaine , Uwe Jannsen

Given a weighted flag variety $w\Sigma(\mu,u)$ corresponding to chosen fixed parameters $\mu$ and $u$, we present an algorithm to compute lists of all possible projectively Gorenstein $n$-folds, having canonical weight $k$ and isolated…

Algebraic Geometry · Mathematics 2016-02-26 Muhammad Imran Qureshi

We calculate the tangent cones at unity of Schubert varieties for $A_n$, where $n$ is less or equal to four. We state several conjectures for an arbitrary $n$.

Representation Theory · Mathematics 2011-10-12 A. N. Panov , D. Yu. Eliseev

In this paper, we investigate the relationship of F-regular (resp. F-pure) rings and log terminal (resp. log canonical) singularities. Also, we extend the notions of F-regularity and F-purity to "F-singularities of pairs." The notions of…

Algebraic Geometry · Mathematics 2007-05-23 Nobuo Hara , Kei-ichi Watanabe

The $F$-signature of a local ring of prime characteristic is a numerical invariant that detects many interesting properties. For example, this invariant detects (non)singularity and strong $F$-regularity. However, it is very difficult to…

Commutative Algebra · Mathematics 2019-09-30 Holger Brenner , Jack Jeffries , Luis Núñez-Betancourt

In this paper we study flag codes on $\mathbb{F}_q^n$, being $\mathbb{F}_q$ the finite field with $q$ elements. Special attention is given to the connection between the parameters and properties of a flag code and the ones of a family of…

Information Theory · Computer Science 2020-12-21 Clementa Alonso-González , Miguel Ángel Navarro-Pérez

We compute global log canonical thresholds of some smooth Fano threefolds.

Algebraic Geometry · Mathematics 2009-02-08 Ivan Cheltsov , Constantin Shramov

We generalize the work of Jian Song to compute the alpha invariant of any (nef and big) toric line bundle in terms of the associated polytope. We use the analytic version of the computation of the log canonical threshold of monomial ideals…

Algebraic Geometry · Mathematics 2020-11-17 Thibaut Delcroix