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Related papers: A note on quasi-convex functions

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If $u : \Omega\subset \mathbb{R}^d \to {\rm X}$ is a harmonic map valued in a metric space ${\rm X}$ and ${\sf E} : {\rm X} \to \mathbb{R}$ is a convex function, in the sense that it generates an ${\rm EVI}_0$-gradient flow, we prove that…

Metric Geometry · Mathematics 2021-07-21 Hugo Lavenant , Léonard Monsaingeon , Luca Tamanini , Dmitry Vorotnikov

Consider a class of functions of one real variable with the following uniqueness property: if a function f(x) from the class vanishes on a set of positive measure, then f is the zero function. In many instances, we would like to have a…

Classical Analysis and ODEs · Mathematics 2007-05-23 F. Nazarov , M. Sodin , A. Volberg

We provide a new necessary condition for local smoothing estimates for the averaging operator defined by convolution with a measure supported on a smooth non-degenerate curve in $\mathbb{R}^n$ for $n \geq 3$. This demonstrates a limitation…

Classical Analysis and ODEs · Mathematics 2025-05-13 David Beltran , Jonathan Hickman

By considering a fixed point in unit disk $\Delta$, a new class of univalent convex functions is defined. Coefficient inequalities, integral operator and extreme points of this class are obtained.

Complex Variables · Mathematics 2009-04-23 Sh. Najafzadeh , M. Eshaghi Gordji , A. Ebadian

We study scaling function geometry. We show the existence of the scaling function of a geometrically finite one-dimensional mapping. This scaling function is discontinuous. We prove that the scaling function and the asymmetries at the…

Dynamical Systems · Mathematics 2008-02-03 Yunping Jiang

In the optimization of convex domains under a PDE constraint numerical difficulties arise in the approximation of convex domains in $\mathbb{R}^3$. Previous research used a restriction to rotationally symmetric domains to reduce shape…

Numerical Analysis · Mathematics 2023-11-23 Sören Bartels , Hedwig Keller , Gerd Wachsmuth

Most approximation methods in high dimensions exploit smoothness of the function being approximated. These methods provide poor convergence results for non-smooth functions with kinks. For example, such kinks can arise in the uncertainty…

Numerical Analysis · Mathematics 2019-02-19 Barbara Fuchs , Jochen Garcke

Weighted cone-volume functionals are introduced for the convex polytopes in $\mathbb{R}^n$. For these functionals, geometric inequalities are proved and the equality conditions are characterized. A variety of corollaries are derived,…

Metric Geometry · Mathematics 2023-07-07 Steven Hoehner , Jeff Ledford

The theory of quasi-arithmetic means is a powerful tool in the study of covariance functions across space-time. In the present study we use quasi-arithmetic functionals to make inferences about the permissibility of averages of functions…

Probability · Mathematics 2007-06-13 E. Porcu , J. Mateu , G. Christakos

In this paper, we establish the sharp $k$-broad estimate for a class of phase functions satisfying the homogeneous convex conditions. As an application, we obtain improved local smoothing estimates for the half-wave operator in dimensions…

Analysis of PDEs · Mathematics 2023-04-11 Chuanwei Gao , Bochen Liu , Changxing Miao , Yakun Xi

In this article, we study the set of potential functions on noncompact quasi-Einstein manifolds. We show that the space of all positive potential functions on a three-dimensional noncompact quasi-Einstein manifold has dimension at most two,…

Differential Geometry · Mathematics 2025-12-11 Jaciane Gonçalves

The notions of quasiconvexity, Wright convexity and convexity for functions defined on a metric Abelian group are introduced. Various characterizations of such functions, the structural properties of the functions classes so obtained are…

Classical Analysis and ODEs · Mathematics 2020-11-23 Włodzimierz Fechner , Zsolt Páles

Classical theory for quasi-Newton schemes has focused on smooth deterministic unconstrained optimization while recent forays into stochastic convex optimization have largely resided in smooth, unconstrained, and strongly convex regimes.…

Optimization and Control · Mathematics 2020-11-03 Afrooz Jalilzadeh , Angelia Nedich , Uday V. Shanbhag , Farzad Yousefian

The main goal of this paper is to present results of existence and non-existence of convex functions on Riemannian manifolds and, in the case of the existence, we associate such functions to the geometry of the manifold. Precisely, we prove…

Differential Geometry · Mathematics 2016-12-13 J. X. Cruz Neto , Ítalo Melo , Paulo Sousa

We propose and analyze numerical schemes for the gradient flow of $Q$-tensor with the quasi-entropy. The quasi-entropy is a strictly convex, rotationally invariant elementary function, giving a singular potential constraining the…

Numerical Analysis · Mathematics 2021-10-22 Yanli Wang , Jie Xu

Let $C$ be a compact convex subset of $\mathbb{R}^n$, $f:C\to\mathbb{R}$ be a convex function, and $m\in\{1, 2, ..., \infty\}$. Assume that, along with $f$, we are given a family of polynomials satisfying Whitney's extension condition for…

Classical Analysis and ODEs · Mathematics 2019-03-05 Daniel Azagra , Carlos Mudarra

In this paper, we introduce new properties of the relative interior calculus for nearly convex sets, functions, and set-valued mappings. These properties are important for the development of duality theory in optimization. Then we…

Optimization and Control · Mathematics 2023-03-15 Nguyen Quang Huy , Nguyen Mau Nam , Nguyen Dong Yen

Let F be a class of functions with the uniqueness property: if a function f in F vanishes on a set of positive measure, then f is the zero function. In many instances, we would like to have a quantitative version of this property, e.g. a…

Classical Analysis and ODEs · Mathematics 2007-05-23 Alexander Borichev , Fedor Nazarov , Mikhail Sodin

This paper presents a noncommutative theory of symmetric functions, based on the notion of quasi-determinant. We begin with a formal theory, corresponding to the case of symmetric functions in an infinite number of independent variables.…

High Energy Physics - Theory · Physics 2008-02-03 Israel Gelfand , D. Krob , Alain Lascoux , B. Leclerc , V. S. Retakh , J. -Y. Thibon

Riemannian Geometry, Topology and Dynamics permit to introduce partially defined holomorphic functions on the variety of representations of the fundamental group of a manifold. The functions we consider are the complex valued Ray-Singer…

Differential Geometry · Mathematics 2007-05-23 Dan Burghelea , Stefan Haller