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Related papers: On closed range for $\bar{\partial}$

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A characterization of non-hyperbolic pseudoconvex Reinhardt domains in $\mathbb C^2$ for which the answer to the Serre problem is positive is given.

Complex Variables · Mathematics 2012-06-07 Lukasz Kosinski

In this paper we study holomorphic approximation using boundary value problems for $\bar\partial$ on an annulus in the Hilbert space setting. The associated boundary conditions for $\bar\partial$ are the mixed boundary problems on an…

Complex Variables · Mathematics 2020-01-14 Christine Laurent-Thiébaut , Mei-Chi Shaw

We show that every bounded pseudoconvex domain with H\"older boundary in $\mathbb C^n$ is hyperconvex.

Complex Variables · Mathematics 2021-02-26 Bo-Yong Chen

Criterion for a companion matrix to have a certain number of flat portions on the boundary of its numerical range is given. The criterion is specialized to the cases of 3-by-3 and 4-by-4 matrices. In the latter case, it is proved that a…

Functional Analysis · Mathematics 2011-07-18 Jeffrey Eldred , Leiba Rodman , Ilya M. Spitkovsky

We study the problem of the boundary behaviour of the Bergman kernel and the Bergman completeness in some classes of bounded pseudoconvex domains, which contain also non-hyperconvex domains. Among the classes for which we prove the Bergman…

Complex Variables · Mathematics 2007-05-23 M. Jarnicki , P. Pflug , W. Zwonek

Several new verifiable conditions are established for block matrices with scalar diagonal blocks to have the numerical range equal the convex hull of at most k ellipses where k by k is the size of the smaller diagonal block. For k = 2,…

Functional Analysis · Mathematics 2020-02-25 Titas Geryba , Ilya M. Spitkovsky

In this paper, we consider the problem of solving the $\partial \bar{\partial}$ with prescribed support for forms or currents in a domain $\Omega$ of an complex manifold $X$.

Complex Variables · Mathematics 2025-12-01 Winnie Ossete Ingoba , Souhaibou Sambou , Salomon Sambou

Often some interesting or simply curious points are left out when developing a theory. It seems that one of them is the existence of an upper bound for the fraction of area of a convex and closed plane area lying outside a circle with which…

General Mathematics · Mathematics 2007-05-23 Jose M. Pacheco

We construct a class of bounded domains, on which the squeezing function is not uniformly bounded from below near a smooth and pseudoconvex boundary point.

Complex Variables · Mathematics 2017-04-11 John Erik Fornaess , Feng Rong

There exist several interesting results in the literature on subnormal operator tuples having their spectral properties tied to the geometry of strictly pseudoconvex domains or to that of bounded symmetric domains in $\C^n$. We introduce a…

Functional Analysis · Mathematics 2016-12-20 Ameer Athavale

We solve the $\partial \bar{\partial}$-problem for a form with distribution boundary value on a Levi flat unbounded domain of $\mathbb{C}^n$ with the complementary is also Levi flat and unbounded.

Complex Variables · Mathematics 2018-05-24 Souhaibou Sambou , Salomon Sambou , Winnie Ossete Ingoba

Let M be a smooth, compact, orientable, weakly pseudoconvex manifold of dimension 3, embedded in C^N (N greater than or equal to 2), of codimension one or more in C^N, and endowed with the induced CR structure. Assuming that the tangential…

Complex Variables · Mathematics 2012-11-12 Joseph J. Kohn , Andreea Nicoara

We obtain a sufficient condition for the convexity of quaternionic numerical range for complex matrices in terms of its complex numerical range. It is also shown that the Bild coincides with complex numerical range for real matrices. From…

Functional Analysis · Mathematics 2019-04-08 Luís Carvalho , Cristina Diogo , Sérgio Mendes

For certain annuli in $\mathbb{C}^n$, $n\geq 2$, with non-smooth holes, we show that the $\bar{\partial}$-operator from $L^2$ functions to $L^2$ $(0,1)$-forms has closed range. The holes admitted include products of pseudoconvex domains and…

Complex Variables · Mathematics 2016-08-04 Debraj Chakrabarti , Christine Laurent-Thiébaut , Mei-Chi Shaw

We study bounded pseudoconvex domains in complex Euclidean spaces. We find analytical necessary conditions and geometric sufficient conditions for a domain being of trivial Diederich--Forn\ae ss index (i.e. the index equals to 1). We also…

Complex Variables · Mathematics 2017-09-21 Bingyuan Liu

Given a polynomial function $f \colon \mathbb{R}^n \rightarrow \mathbb{R}$ and a unbounded basic closed semi-algebraic set $S \subset \mathbb{R}^n,$ in this paper we show that the conditions listed below are characterized exactly in terms…

Optimization and Control · Mathematics 2019-03-12 Tien-Son Pham

We construct a strictly pseudoconvex domain with smooth boundary whose squeezing function is not plurisubharmonic.

Complex Variables · Mathematics 2016-04-28 John Erik Fornæss , Nikolay Shcherbina

It is well known that elliptic estimates fail for the $\bar\partial$-Neumann problem. Instead, the best that one can hope for is that derivatives in every direction but one can be estimated by the associated Dirichlet form, and when this…

Complex Variables · Mathematics 2022-01-11 Phillip S. Harrington , Andrew Raich

This short paper gives a constraint on Chern classes of closed strictly pseudoconvex CR manifolds (or equivalently, closed holomorphically fillable contact manifolds) of dimension at least five. We also see that our result is ''optimal''…

Complex Variables · Mathematics 2020-01-22 Yuya Takeuchi

We give an explicit upper bound for the algebraic degree and an explicit lower bound for the absolute value of the minimum of a polynomial function on a compact connected component of a basic closed semialgebraic set when this minimum is…

Algebraic Geometry · Mathematics 2011-12-05 Gabriela Jeronimo , Daniel Perrucci , Elias Tsigaridas