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In this paper we establish a close relationship between the spherical functions of the $n$-dimensional sphere $S^n\simeq\SO(n+1)/\SO(n)$ and the spherical functions of the $n$-dimensional real projective space…

Representation Theory · Mathematics 2014-07-01 Juan Alfredo Tirao , Ignacio Nahuel Zurrián

Recently geometric hypergraphs that can be defined by intersections of pseudohalfplanes with a finite point set were defined in a purely combinatorial way. This led to extensions of earlier results about points and halfplanes to…

Combinatorics · Mathematics 2024-02-14 Balázs Keszegh

This paper presents a study of generalized polyhedral convexity under basic operations on multifunctions. We address the preservation of generalized polyhedral convexity under sums and compositions of multifunctions, the domains and ranges…

Optimization and Control · Mathematics 2023-10-19 Nguyen Ngoc Luan , Nguyen Mau Nam , Nguyen Dong Yen

A complete classification of continuous, dually epi-translation invariant, and rotation equivariant valuations on convex functions is established. This characterizes the recently introduced functional Minkowski vectors, which naturally…

Metric Geometry · Mathematics 2025-04-24 Mohamed A. Mouamine , Fabian Mussnig

We give a systematic and thorough study of geometric notions and results connected to Minkowski's measure of symmetry and the extension of the well-known Minkowski functional to arbitrary, not necessarily symmetric convex bodies K on any…

Classical Analysis and ODEs · Mathematics 2007-05-23 Szilard Gy. Revesz

In this paper, we first investigate weighted Minkowski type inequalities for nearly spherical sets in space forms, focusing on the sets that are $C^1$-close to geodesic spheres. Our results generalize the work of \cite{G22} by incorporating…

Differential Geometry · Mathematics 2026-04-29 Weimin Sheng , Yinhang Wang

We give a general expression of spherical functions on $p$-adic homogeneous spaces of $G$, based on data of $G$ and functional equations of spherical functions. Then, we show a unified method to obtain functional equations of spherical…

Number Theory · Mathematics 2009-04-25 Yumiko Hironaka

We study the convexity properties of the generalized trigonometric functions considered as functions of parameter. We show that $p\to\sin_p(y)$ and $p\to\cos_p(y)$ are log-concave on the appropriate intervals while $p\to\tan_p(y)$ is…

Classical Analysis and ODEs · Mathematics 2014-02-17 D. B. Karp , E. G. Prilepkina

Generalized smooth functions are a possible formalization of the original historical approach followed by Cauchy, Poisson, Kirchhoff, Helmholtz, Kelvin, Heaviside, and Dirac to deal with generalized functions. They are set-theoretical…

Functional Analysis · Mathematics 2016-06-14 Paolo Giordano , Michael Kunzinger

In 1966, P. G\"unther proved the following result: Given a continuous function $f$ on a compact surface $M$ of constant curvature -1 and its periodic lift $\tilde{f}$ to the universal covering, the hyperbolic plane, then the averages of the…

Combinatorics · Mathematics 2009-10-01 Femke Douma

In this paper we have generalized the notion of $\lambda$-radial contraction in complete Riemannian manifold and developed the concept of $p^\lambda$-convex function. We have also given a counter example proving the fact that in general…

Differential Geometry · Mathematics 2019-07-08 Absos Ali Shaikh , Chandan Kumar Mondal , Akhlad Iqbal

To every log-concave function $f$ one may associate a pair of measures $(\mu_{f},\nu_{f})$ which are the surface area measures of $f$. These are a functional extension of the classical surface area measure of a convex body, and measure how…

Metric Geometry · Mathematics 2025-02-25 Tomer Falah , Liran Rotem

In this paper we study some relationships between polyhedral convex sets (PCS) and generalized polyhedral convex sets (GPCS). In particular, we clarify by a counterexample that the necessary and sufficient conditions for the separation of a…

Optimization and Control · Mathematics 2022-12-26 Nguyen Ngoc Luan , Nguyen Mau Nam , Nguyen Nang Thieu , Nguyen Dong Yen

The conchoid of a surface $F$ with respect to given fixed point $O$ is roughly speaking the surface obtained by increasing the radius function with respect to $O$ by a constant. This paper studies {\it conchoid surfaces of spheres} and…

Algebraic Geometry · Mathematics 2014-01-10 Martin Peternell , David Gruber , Juana Sendra

Parallel to the main results of [13] and [14], which explore the equivalence between prox-regularity, the exterior sphere condition, and $S$-convexity, we present novel characterizations of the $r$-strong convexity property, namely, of the…

Metric Geometry · Mathematics 2025-01-15 Chadi Nour , Jean Takche

In this paper, we derive new sharp weighted Alexandrov-Fenchel and Minkowski inequalities for smooth, closed hypersurfaces under various convexity assumptions in Euclidean, spherical, and hyperbolic spaces. These inequalities extend…

Differential Geometry · Mathematics 2026-04-14 Kwok-Kun Kwong , Yong Wei

We introduce and study a new class of $\eps$-convex bodies (extending the class of convex bodies) in metric and normed linear spaces. We analyze relations between characteristic properties of convex bodies, demonstrate how $\eps$-convex…

Differential Geometry · Mathematics 2016-02-03 Vladimir Golubyatnikov , Vladimir Rovenski

In this paper we extend some notions, previously defined for log-concave functions, to the larger domain of so-called {\alpha}-concave functions. We begin with a detailed discussion of support functions - first for log-concave functions,…

Functional Analysis · Mathematics 2012-10-17 Liran Rotem

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

Minkowski's classical existence theorem provides necessary and sufficient conditions for a Borel measure on the unit sphere of Euclidean space to be the surface area measure of a convex body. The solution is unique up to a translation. We…

Metric Geometry · Mathematics 2020-08-18 Rolf Schneider