English
Related papers

Related papers: Variation of log canonical thresholds in linear sy…

200 papers

We establish a nonasymptotic lower bound on the $L_2$ minimax risk for a class of generalized linear models. It is further shown that the minimax risk for the canonical linear model matches this lower bound up to a universal constant.…

Statistics Theory · Mathematics 2020-06-11 Kuan-Yun Lee , Thomas A. Courtade

Over an algebraically closed field of positive characteristic, we classify smooth Fano threefolds of Picard number one whose anti-canonical linear systems are not very ample. Furthermore, we also prove that an anti-canonically embedded Fano…

Algebraic Geometry · Mathematics 2026-03-13 Hiromu Tanaka

There is a proposition due to Koll\'ar 1997 on computing log canonical thresholds of certain hypersurface germs using weighted blowups, which we extend to weighted blowups with non-negative weights. Using this, we show that the log…

Algebraic Geometry · Mathematics 2025-09-03 Erik Paemurru

We classify all Gorenstein Fano threefolds with at worst canonical singularities for which the anticanonical system has a nonempty base locus.

Algebraic Geometry · Mathematics 2007-05-23 Priska Jahnke , Ivo Radloff

We conjecture that the number of components of the fiber over infinity of Landau--Ginzburg model for a smooth Fano variety $X$ equals the dimension of the anticanonical system of $X$. We verify this conjecture for log Calabi--Yau…

Algebraic Geometry · Mathematics 2023-02-16 Ivan Cheltsov , Victor Przyjalkowski

In this note we collect some results on the deformation theory of toric Fano varieties.

Algebraic Geometry · Mathematics 2022-06-22 Andrea Petracci

A conjecture of Batyrev and Manin relates arithmetic properties of varieties with ample anticanonical class to geometric invariants; in particular, counting functions defined by metrized ample line bundles and the corresponding asymptotics…

Algebraic Geometry · Mathematics 2014-09-23 Brian Lehmann , Sho Tanimoto , Yuri Tschinkel

We introduce real log canonical threshold and real jumping numbers for real algebraic functions. A real jumping number is a root of the $b$-function up to a sign if its difference with the minimal one is less than 1. The real log canonical…

Algebraic Geometry · Mathematics 2007-07-25 Morihiko Saito

We show that generalized log canonical thresholds for complex analytic spaces satisfy the ACC and we characterize the accumulation points.

Algebraic Geometry · Mathematics 2023-03-03 Christopher Hacon , Lingyao Xie

We investigate birational boundedness of Fano varieties and Fano fibrations. We establish an inductive step towards birational boundedness of Fano fibrations via conjectures related to boundedness of Fano varieties and Fano fibrations. As…

Algebraic Geometry · Mathematics 2019-12-02 Chen Jiang

We prove the boundedness theorem for Fano threefolds with log-terminal singularities of any fixed index. This is an improvement of our earlier result, where we required additionally that the variety is Q-factorial, with Picard number 1. The…

Algebraic Geometry · Mathematics 2007-05-23 Alexandr Borisov

We introduce the class of weakly log canonical singularities, a natural generalization of semi-log canonical singularities. Toric varieties (associated to toric face rings, possibly non-normal or reducible) which have weakly (semi-) log…

Algebraic Geometry · Mathematics 2017-11-02 Florin Ambro

Let $(X,D)$ be log canonical pair such $\dim X = 3$ and the divisor $-(K_X + D)$ is nef and big. For a special class of such $(X,D)$'s we prove that the linear system $|-n(K_{X}+D)|$ is free for $n \gg 0$.

Algebraic Geometry · Mathematics 2010-02-01 Ilya Karzhemanov

We construct canonical heights of subvarieties for dynamical system of several morphisms associated with line bundles defined over a number field, and study some of their properties. We also construct invariant currents for such systems…

Number Theory · Mathematics 2007-05-23 Shu Kawaguchi

We give the first examples of flat fiber type contractions of Fano manifolds onto varieties that are not weak Fano, and we prove that these morphisms are Fano conic bundles. We also review some known results about the interaction between…

Algebraic Geometry · Mathematics 2017-03-09 Eleonora Anna Romano

We give tight bounds for logarithmic mean. We also give new Frobenius norm inequalities for two positive semidefinite matrices. In addition, we give some matrix inequalities on matrix power mean.

Functional Analysis · Mathematics 2014-02-05 Shigeru Furuichi , Kenjiro Yanagi

For Fano varieties of various singularities such as canonical and terminal, we construct examples with large Fano index. By low-dimensional evidence, we conjecture that our examples have the largest Fano index for all dimensions.

Algebraic Geometry · Mathematics 2023-08-15 Chengxi Wang

Consider a smooth log Fano variety over the function field of a curve. Suppose that the boundary has positive normal bundle. Choose an integral model over the curve. Then integral points are Zariski dense, after removing an explicit finite…

Algebraic Geometry · Mathematics 2009-11-13 Brendan Hassett , Yuri Tschinkel

We give some bounds on the anticanonical degrees of Fano varieties with Picard number 1 and mild singularities, extending results of Koll\'ar et al. from the early 90's and improving them even in the smooth case. The proof is based on a…

Algebraic Geometry · Mathematics 2007-05-23 Ziv Ran , Herb Clemens

The purpose of this paper is to give basic tools for the classification of nonsingular toric Fano varieties by means of the notions of primitive collections and primitive relations due to Batyrev. By using them we can easily deal with…

Algebraic Geometry · Mathematics 2007-05-23 Hiroshi Sato
‹ Prev 1 4 5 6 7 8 10 Next ›