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The purpose of this paper is to present some multidimensional fixed-point theorems and their applications. For this, we provide a multidimensional fixed point theorem and then using this theorem we prove the existence and uniqueness of a…

Functional Analysis · Mathematics 2021-07-28 H. Akhadkulov , S. Akhatkulov , T. Y. Ying , R. Tilavov

Let $X$ be a smooth projective surface with Picard number 1. Let $L$ be the ample generator of the N\'eron-Severi group of $X$. Given an integer $r\ge 2$, we prove lower bounds for the Seshadri constant of $L$ at $r$ general points in $X$.

Algebraic Geometry · Mathematics 2016-10-20 Krishna Hanumanthu

Working over the complex field and formalizing and sharpening approaches introduced by several authors, we give a method for verifying when a divisor on a blow up of P^2 at general points is nef. The method is useful both theoretically and…

Algebraic Geometry · Mathematics 2007-09-26 B. Harbourne , J. Roe

Let $X$ be a smooth variety and let $L$ be an ample line bundle on $X$. If $\pi^{alg}_{1}(X)$ is large, we show that the Seshadri constant $\epsilon(p^{*}L)$ can be made arbitrarily large by passing to a finite \'etale cover…

Complex Variables · Mathematics 2019-02-25 Gabriele Di Cerbo , Luca F. Di Cerbo

Generative models, particularly Generative Adversarial Networks (GANs), often suffer from a lack of output diversity, frequently generating similar samples rather than a wide range of variations. This paper introduces a novel generalization…

Machine Learning · Computer Science 2026-03-20 Muhammad Mubashar , Fabio Cuzzolin

In this paper, we establish some new variants of fixed point theorems for a large class of countably nonexpansive multi-valued mappings. Some fixed point theorems for the sum and the product of three multi-valued mappings defined on…

Functional Analysis · Mathematics 2024-01-19 Khaled Ben Amara , Aref Jeribi , Najib Kaddachi

We study effective global generation properties of projectivizations of curve semistable vector bundles over curves and abelian varieties.

Algebraic Geometry · Mathematics 2024-05-21 Jiaming Chen , Alex Küronya , Yusuf Mustopa , Jakob Stix

We develop a geometric scattering theory for a geometrically finite group acting on (a vector bundle over) a symmetric space of negative curvature. In particular, we obtain the meromorphic continuation of Eisenstein series and scattering…

Differential Geometry · Mathematics 2007-11-28 Ulrich Bunke , Martin Olbrich

We establish an improvement of Philippon's zero estimates primarily in the multiplicity setting. The improvement is made possible by a more geometric approach and in particular the use of Seshadri constants.

Number Theory · Mathematics 2007-10-15 Michael Nakamaye , Nicolas Ratazzi

We present an effective global generation result for direct images of pluricanonical bundles in mixed characteristic. This is a mixed characteristic analog of Ejiri's theorem in positive characteristic and the theorem of Popa and Schnell…

Algebraic Geometry · Mathematics 2026-05-19 Hirotaka Onuki

Deep generative models have shown immense potential in generating unseen data that has properties of real data. These models learn complex data-generating distributions starting from a smaller set of latent dimensions. However, generative…

Solar and Stellar Astrophysics · Physics 2026-02-23 Subhamoy Chatterjee , Andres Munoz-Jaramillo , Anna Malanushenko

In this article, we give a description of the closed cone of curves of the projective bundle $\mathbb{P}(E)$ over a smooth projective variety $X$. Using duality, we then calculate the nef cone of divisors in $\mathbb{P}(E)$ over some…

Algebraic Geometry · Mathematics 2022-08-19 Snehajit Misra , Nabanita Ray

Let $X$ be a complex nonsingular projective surface and let $L$ be an ample line bundle on $X$. We study multi-point Seshadri constants of $L$ at singular points of certain arrangements of curves on $X$. We pose some questions about such…

Algebraic Geometry · Mathematics 2024-07-19 Krishna Hanumanthu , Praveen Kumar Roy , Aditya Subramaniam

We show that the anti-canonical bundle of any $\mathbb Q$-factorial surface is numerically effective if and only if it is pseudo-effective. To prove this, we establish a numerical non-vanishing theorem for surfaces polarized with…

Algebraic Geometry · Mathematics 2024-10-22 Jihao Liu , Lingyao Xie

This article deals with the conjugate gradient method on a Riemannian manifold with interest in global convergence analysis. The existing conjugate gradient algorithms on a manifold endowed with a vector transport need the assumption that…

Optimization and Control · Mathematics 2016-06-20 Hiroyuki Sato , Toshihiro Iwai

We consider global generation of sheaves of coinvariants on the moduli space of curves given by simple modules over certain vertex operator algebras, extending results for affine VOAs at integrable levels on stable pointed rational curves.…

Algebraic Geometry · Mathematics 2022-08-10 Chiara Damiolini , Angela Gibney

T. Szemberg proposed in 2001 a generalization to arbitrary varieties of M. Nagata's 1959 open conjecture, which claims that the Seshadri constant of r>9 very general points of the projective plane is maximal. Here we prove that Nagata's…

Algebraic Geometry · Mathematics 2007-05-23 Joaquim Roé

We present new criteria on the existence of fixed points that combine some monotonicity assumptions with the classical fixed point index theory. As an illustrative application, we use our theoretical results to prove the existence of…

Classical Analysis and ODEs · Mathematics 2014-12-12 Alberto Cabada , José Ángel Cid , Gennaro Infante

We relate finite generation of cones, monoids, and ideals in increasing chains (the local situation) to equivariant finite generation of the corresponding limit objects (the global situation). For cones and monoids there is no analog of…

Combinatorics · Mathematics 2022-04-26 Thomas Kahle , Dinh Van Le , Tim Römer

Let $X$ be a smooth complex projective curve and let $E$ be a vector bundle on $X$ which is not semistable. We consider a flag bundle $\pi: \text{Fl}(E) \to X$ parametrizing certain flags of fibers of $E$. The dimensions of the successive…

Algebraic Geometry · Mathematics 2024-04-10 Krishna Hanumanthu , Jagadish Pine