中文
相关论文

相关论文: On the maximum dual volume of a canonical Fano pol…

200 篇论文

Let V be an even dimensional vector space with a non degenerate quadratic form. We denote by X the variety of maximal isotropic subspaces in V (in fact one of its two connected components). In this paper, we prove the irreducibility of the…

代数几何 · 数学 2007-05-23 Nicolas Perrin

Given a set $S \subseteq \mathbb{R}^d$, a hollow polytope has vertices in $S$ but contains no other point of $S$ in its interior. We prove upper and lower bounds on the maximum number of vertices of hollow polytopes whose facets are…

度量几何 · 数学 2025-04-25 Srinivas Arun , Travis Dillon

For natural numbers $n$ and $l > d \geq 2$, let $ES_d(l,n)$ be the minimum $N$ such that any set of at least $N$ points in $\mathbb{R}^d$ contains either $l$ points contained in a common $(d-1)$-dimensional hyperplane or $n$ points in…

组合数学 · 数学 2025-06-02 Koki Furukawa

A subset of the Hamming cube over $n$-letter alphabet is said to be $d$-maximal if its diameter is $d$, and adding any point increases the diameter. Our main result shows that each $d$-maximal set is either of size at most $(n+o(n))^d$ or…

组合数学 · 数学 2025-07-16 Boris Bukh , Aleksandre Saatashvili

We prove that $\operatorname{vol}(S^{d})/8$ is the highest volume of a pair of $d$-dimensional isospectral and non-isometric spherical orbifolds for any $d\geq5$. Furthermore, we show that $\operatorname{vol}(S^{2n-1})/11$ is the highest…

微分几何 · 数学 2025-02-05 Alfredo Álzaga , Emilio A. Lauret

In this short note we give a construction of an infinite series of Delone simplices whose relative volume grows super-exponentially with their dimension. This dramatically improves the previous best lower bound, which was linear.

组合数学 · 数学 2007-05-23 F. Santos , A. Schuermann , F. Vallentin

We derive various sharp upper bounds for the $p$-capacity of a smooth compact set $K$ in the hyperbolic space $\mathbb{H}^n$ and the Euclidean space $\mathbb{R}^n$. Firstly, using the inverse mean curvature flow, for the mean convex and…

微分几何 · 数学 2023-06-16 Haizhong Li , Ruixuan Li , Changwei Xiong

The celebrated upper bound theorem of McMullen determines the maximal number of extreme points of a polyhedron in terms of its dimension and the number of constraints which define it, showing that the maximum is attained by the polar of the…

组合数学 · 数学 2010-11-04 Xavier Allamigeon , Stephane Gaubert , Ricardo D. Katz

We prove that for any smooth projective $3$-fold of general type with canonical volume greater than $12^6$, the image of its bicanonical map has dimension at least $2$. We also study pluricanonical maps of $3$-folds of general type with…

代数几何 · 数学 2026-05-19 Chen Jiang , Ziqi Liu

We give an effective upper bound on the h^*-polynomial of a lattice polytope in terms of its degree and leading coefficient, confirming a conjecture of Batyrev. We deduce this bound as a consequence of a strong Cayley decomposition theorem…

组合数学 · 数学 2010-02-14 Christian Haase , Benjamin Nill , Sam Payne

We prove an upper bound for the volume of maximal analytic sets on which the generic Lelong number of a closed positive current is positive. As a particular case, we give a uniform upper bound on the volume of the singular locus of an…

复变函数 · 数学 2023-06-27 Do Duc Thai , Duc-Viet Vu

This paper is devoted to the study of lower and upper bounds for the number of vertices of the polytope of $n\times n\times n$ stochastic tensors (i.e., triply stochastic arrays of dimension $n$). By using known results on polytopes (i.e.,…

组合数学 · 数学 2017-02-15 Zhongshan Li , Fuzhen Zhang , Xiao-Dong Zhang

We show that there is no compact hyperbolic Coxeter d-polytope with d+4 facets for d>7. This bound is sharp: examples of such polytopes up to dimension 7 were found by Bugaenko (1984). We also show that in dimension d=7 the polytope with 11…

度量几何 · 数学 2019-10-25 Anna Felikson , Pavel Tumarkin

We study the normalized volume of toric singularities. As it turns out, there is a close relation to the notion of (non-symmetric) Mahler volume from convex geometry. This observation allows us to use standard tools from convex geometry,…

代数几何 · 数学 2021-11-03 Joaquín Moraga , Hendrik Süß

We provide a sharp upper bound on the quotient of the rank of an A-hypergeometric system with a three-dimensional torus action by the normalized volume of A; in this case, the upper bound is two.

代数几何 · 数学 2023-01-12 Christine Berkesch , María-Cruz Fernández-Fernández

We define Q-normal lattice polytopes. Natural examples of such polytopes are Cayley sums of strictly combinatorially equivalent lattice polytopes, which correspond to particularly nice toric fibrations, namely toric projective bundles. In a…

代数几何 · 数学 2009-04-01 Alicia Dickenstein , Sandra Di Rocco , Ragni Piene

We study the calculation of the volume of the polytope B_n of n by n doubly stochastic matrices; that is, the set of real non-negative matrices with all row and column sums equal to one. We describe two methods. The first involves a…

组合数学 · 数学 2007-05-23 Clara S. Chan , David P. Robbins

The diameter of a strongly connected $d$-dimensional simplicial complex is the diameter of its dual graph. We provide a probabilistic proof of the existence of $d$-dimensional simplicial complexes with diameter $ (\frac{1}{d \cdot d!} -…

组合数学 · 数学 2022-04-27 Tom Bohman , Andrew Newman

We present a combinatorial criterion on reflexive polytopes of dimension 3 which gives a local-to-global obstruction for the smoothability of the corresponding Fano toric threefolds. As a result, we show examples of singular Gorenstein Fano…

代数几何 · 数学 2021-09-02 Andrea Petracci

Using $\delta$-invariants and Newton--Okounkov bodies, we derive the optimal volume upper bound for K\"ahler manifolds with positive Ricci curvature, from which we get a new characterization of the complex projective space.

微分几何 · 数学 2020-09-30 Kewei Zhang
‹ 上一页 1 8 9 10 下一页 ›