English
Related papers

Related papers: On compact sets possessing $q$-convex functions

200 papers

We study fine properties of quasiplurisubharmonic functions on compact K\"ahler manifolds. We define and study several intrinsic capacities which characterize pluripolar sets and show that locally pluripolar sets are globally…

Complex Variables · Mathematics 2007-05-23 Vincent Guedj , Ahmed Zeriahi

Let G be a complex reductive Lie group acting on a compact K\"ahler manifold X and assume that the action of a maximal compact subgroup K of G is Hamiltonian. For each extreme point of the convex hull of the momentum map image, there is an…

Complex Variables · Mathematics 2025-05-13 Peter Heinzner , Christian Zöller

A subclass of complex-valued close-to-convex harmonic functions that are univalent and sense-preserving in the open unit disc is investigated. The coefficient estimates, growth results, area theorem, boundary behavior, convolution and…

Complex Variables · Mathematics 2012-07-17 Sumit Nagpal , V. Ravichandran

Let $(\phi_t)_{t \geq 0}$ be a semigroup of holomorphic functions in the unit disk $\mathbb{D}$ and $K$ a compact subset of $\mathbb{D}$. We investigate the conditions under which the backward orbit of $K$ under the semigroup exists.…

Complex Variables · Mathematics 2021-12-02 Maria Kourou , Konstantinos Zarvalis

We prove that a closed convex subset $C$ of a complete linear metric space $X$ is polyhedral in its closed linear hull if and only if no infinite subset $A\subset X\backslash C$ can be hidden behind $C$ in the sense $[x,y]\cap C\not =…

Functional Analysis · Mathematics 2011-11-22 Taras Banakh , Ivan Hetman

WDC sets in ${\mathbb R}^d$ were recently defined as sublevel sets of DC functions (differences of convex functions) at weakly regular values. They form a natural and substantial generalization of sets with positive reach and still admit…

Metric Geometry · Mathematics 2017-06-02 Dušan Pokorný , Jan Rataj , Luděk Zajíček

For a compact convex subset K with non-empty interior in a finite-dimensional vector space, let G be the group of all smooth diffeomorphisms of K which fix the boundary of K pointwise. We show that G is a C^0-regular infinite-dimensional…

Group Theory · Mathematics 2016-03-22 Helge Glockner , Karl-Hermann Neeb

In this paper, we show that the CR $Q$-curvature is orthogonal to the space of CR pluriharmonic functions on any closed strictly pseudoconvex CR manifold of dimension at least five. To this end, we obtain a cohomological expression of the…

Differential Geometry · Mathematics 2022-10-13 Yuya Takeuchi

In this paper, the spherical quasi-convexity of quadratic functions on spherically subdual convex sets is studied. Sufficient conditions for spherical quasi-convexity on spherically subdual convex sets are presented. A partial…

Optimization and Control · Mathematics 2020-08-20 Orizon P. Ferreira , Sándor Z. Németh , Lianghai Xiao

We give a proof that there exists a universal constant $K$ such that the disc graph associated to a surface $S$ forming a boundary component of a compact, orientable 3-manifold $M$ is $K$-quasiconvex in the curve graph of $S$. Our proof…

Geometric Topology · Mathematics 2017-03-31 Kate M. Vokes

It is shown that, for any function $g$ that is weakly increasing on compact convex sets and has the property that if $\lambda\ge 0$ and $K^\prime$ is a translate of $\lambda K$ then $g(K^\prime) =\lambda g(K)$, then for any covering…

Metric Geometry · Mathematics 2023-02-27 Jim Lawrence

We prove conditions for the existence of a continuous linear right inverse for a surjective convolution operator in spaces of germs of analytic functions on convex subsets of the complex plane. Considered convex sets have a countable…

Functional Analysis · Mathematics 2018-10-22 S. N. Melikhov , L. V. Khanina

We prove that every closed Bohr-Sommerfeld Lagrangian submanifold $Q$ of a symplectic/K\"ahler manifold $X$ can be realised as a Morse-Bott minimum for some 'convex' exhausting function defined in the complement of a symplectic/complex…

Symplectic Geometry · Mathematics 2018-03-21 Alexandre Vérine

In this paper, we show that the optimal fundamental estimate holds true on a weakly $1$-complete manifold with mild conditions, then we establish the weak Morse inequalities for lower energy forms on the manifold. We also study the case for…

Complex Variables · Mathematics 2024-07-08 Xiquan Peng , Guokuan Shao , Wenxuan Wang

A Peano compactum is a compact metric space having locally connected components such that at most finitely many of them are of diameter greater than any fixed number C>0. Given a compactum K in the extended complex plane, it is known that…

Dynamical Systems · Mathematics 2024-08-14 Jun Luo , Yi Yang , Xiaoting Yao

In this paper we confirm a folklore conjecture which suggests that for a complete noncompact manifold $M$ of finite volume with sectional curvature $-1 \leq K \leq 0$, if the universal cover of $M$ is a visibility manifold, then the…

Geometric Topology · Mathematics 2024-05-30 Ran Ji , Yunhui Wu

We establish the Hodge conjecture for the top dimensional cohomology group with integer coefficients of any $q$-complete complex manifold $X$ with $q<\dim X$. This holds in particular for the complement $X=\mathbb{C}\mathbb{P}^n\setminus A$…

Algebraic Geometry · Mathematics 2016-03-09 Franc Forstneric , Jaka Smrekar , Alexandre Sukhov

In this article we show the following result: if $C$ is an $n$-dimensional convex and compact subset, $f:C\rightarrow[0,\infty)$ is concave, and $\phi:[0,\infty)\rightarrow[0,\infty)$ is a convex function with $\phi(0)=0$, we then…

Functional Analysis · Mathematics 2021-01-29 Bernardo González Merino

Let M be a smooth CR manifold of CR dimension n and CR codimension k, which is not compact, but has the local extension property E. We introduce the notion of "elementary pseudoconcavity" for M, which extends to CR manifolds the concept of…

Complex Variables · Mathematics 2007-10-29 C. Denson Hill , Mauro Nacinovich

Let $G \subset {\mathbb R}^{n}$ be an open convex set which is either bounded or contains a translation of a convex cone with nonempty interior. It is known that then, for every modulus $\omega$, every function on $G$ which is both…

Classical Analysis and ODEs · Mathematics 2021-03-02 Václav Kryštof , Luděk Zajíček