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Related papers: An Example on $s$-H-Convexity in $\mathbb{C}^2$

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We give examples of pseudoconvex domains of finite type in $\mathbb{C}^2$ where the Kohn algorithm for subelliptic estimates fails to yield an effective lower bound for the order of subellipticity in terms of the type. We show how to modify…

Complex Variables · Mathematics 2020-03-03 Martino Fassina

We show the following symmetry property of a bounded Reinhardt domain $\Omega$ in $\mathbb{C}^{n+1}$: let $M=\partial\Omega$ be the smooth boundary of $\Omega$ and let $h$ be the Second Fundamental Form of $M$; if the coefficient $h(T,T)$…

Differential Geometry · Mathematics 2010-11-23 Vittorio Martino

A conjecture of Fuglede states that a bounded measurable set $\Omega$ in space, of measure 1, can tile space by translations if and only if the Hilbert space $L^2(\Omega)$ has an orthonormal basis consisting of exponentials. If $\Omega$ has…

Classical Analysis and ODEs · Mathematics 2007-05-23 Mihail N. Kolountzakis

In a Riemannian manifold a regular convex domain is said to be $\lambda$-convex if its normal curvature at each point is greater than or equal to $\lambda$. In a Hadamard manifold, the asymptotic behaviour of the quotient…

Differential Geometry · Mathematics 2013-03-21 J. Abardia , E. Gallego

Let $\Omega$ be a domain in $\Ri^d$ with boundary $\Gamma$ and let $d_\Gamma$ denote the Euclidean distance to $\Gamma$. Further let $H=-\divv(C\nabla)$ where $C=(\,c_{kl}\,)>0$ with $c_{kl}=c_{lk}$ are real, bounded, Lipschitz continuous…

Functional Analysis · Mathematics 2019-11-11 Derek W Robinson

Let $\Omega\subset \mathbb{C}^2$ be a bounded convex domain with $C^1$-smooth boundary and $\varphi\in C^1(\overline{\Omega})$ such that $\varphi$ is harmonic on the nontrivial disks in the boundary. We estimate the essential norm of the…

Complex Variables · Mathematics 2021-03-08 Zeljko Cuckovic , Sonmez Sahutoglu

In this paper, we obtain the Gehring-Hayman type theorem on smoothly bounded pseudoconvex domains of finite type in $\mathbb{C}^2$. As an application, we provide a quantitative comparison between global and local Kobayashi distances near a…

Complex Variables · Mathematics 2023-10-17 Haichou Li , Xingsi Pu , Hongyu Wang

Comparing Neumann and Dirichlet eigenvalues of the Laplacian on a bounded domain $\Omega\subseteq\Rbb^n$ is a topic that goes back at least to the work of P\'olya \cite{polya}. We study the effect of the isoperimetric ratio of $\Omega$ on…

Spectral Theory · Mathematics 2025-04-28 Lawford Hatcher

In this paper we find surprisingly small Oka domains in Euclidean spaces $\mathbb C^n$ of dimension $n>1$ at the very limit of what is possible. Under a mild geometric assumption on a closed unbounded convex set $E$ in $\mathbb C^n$ we show…

Complex Variables · Mathematics 2024-11-01 Franc Forstneric , Erlend Fornaess Wold

This paper contains both theoretical results and experimental data on the behavior of the dimensions of the cohomology spaces H^1(G,E_n), where Gamma is a lattice in SL(2,C) and E_n is one of the standard self-dual modules. In the case…

Number Theory · Mathematics 2008-08-11 Tobias Finis , Fritz Grunewald , Paulo Tirao

For any pseudoconvex Runge domain $\Omega\subset\mathbb{C}^2$ we prove that every closed discrete subset in $\Omega$ is contained in a properly embedded complex curve in $\Omega$ with any prescribed topology (possibly infinite).

Complex Variables · Mathematics 2018-01-08 Antonio Alarcon

We consider the class $S^m_\perp(\Omega)$ of $m$-dimensional surfaces in $\bar{\Omega} \subset {\mathbb R}^n$ which intersect $S = \partial \Omega$ orthogonally along the boundary. A piece of an affine $m$-plane in $S^m_\perp(\Omega)$ is…

Differential Geometry · Mathematics 2024-07-22 Ernst Kuwert , Marius Müller

Motivated by the study of the corner singularities in the so-called cavity flow, we establish in this article, the existence and uniqueness of solutions in $L^2(\Omega)^2$ for the Stokes problem in a domain $\Omega,$ when $\Omega$ is a…

Analysis of PDEs · Mathematics 2015-12-04 Makram Hamouda , Roger Temam , Le Zhang

We show that there are functions $f$ in the H\"older class $C^{ { \alpha }}[0,1]$, $1< { \alpha }<2$ such that $f|_{A}$ is not convex, nor concave for any $A { \subset } [0,1]$ with $ { \bar { dim }_M } A> { \alpha }-1$. Our earlier result…

Classical Analysis and ODEs · Mathematics 2017-02-06 Zoltan Buczolich

We give an explicit construction of special strongly pseudoconvex domains in C^n of handlebody type, i.e., domains which are small tubes surrounding the union of a quadratic strongly pseudoconvex domain with an attached totally real handle.…

Complex Variables · Mathematics 2007-05-23 Franc Forstneric , Jernej Kozak

In this paper we study the geometry and the topology of unbounded domains in the Hyperbolic Space $\mathbb{H} ^n$ supporting a bounded positive solution to an overdetermined elliptic problem. Under suitable conditions on the elliptic…

Analysis of PDEs · Mathematics 2015-11-10 José M. Espinar , Alberto Farina , Laurent Mazet

We give an example of a pseudoconvex domain in a complex manifold whose $L^2$-Dolbeault cohomology is non-Hausdorff, yet the domain is Stein. The domain is a smoothly bounded Levi-flat domain in a two complex-dimensional compact complex…

Complex Variables · Mathematics 2015-03-03 Debraj Chakrabarti , Mei-Chi Shaw

F. Wehrung has asked: Given a family $\mathcal{C}$ of subsets of a set $\Omega$, under what conditions will there exist a total ordering on $\Omega$ under which every member of $\mathcal{C}$ is convex? <p> Note that if $A$ and $B$ are…

Combinatorics · Mathematics 2020-11-17 George M. Bergman

This paper deals with some geometrical properties of solutions of some semilinear elliptic equations in bounded convex domains or convex rings. Constant boundary conditions are imposed on the single component of the boundary when the domain…

Analysis of PDEs · Mathematics 2013-04-24 Francois Hamel , Nikolai Nadirashvili , Yannick Sire

We construct nontrivial unbounded domains $\Omega$ in the hyperbolic space $\mathbb{H}^N$, $N \in \{2,3,4\}$, bifurcating from the complement of a ball, such that the overdetermined elliptic problem \begin{equation} -\Delta_{\mathbb{H}^N}…

Analysis of PDEs · Mathematics 2024-05-08 Guowei Dai , Pieralberto Sicbaldi , Yong Zhang