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Related papers: Another proof of the corona theorem

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In the present paper we introduce analogs of almost periodic functions on the unit circle. We study certain uniform algebras generated by such functions, prove corona theorems for them and describe their maximal ideal spaces.

Complex Variables · Mathematics 2007-05-23 A. Brudnyi , D. Kinzebulatov

We prove that the $L_4$ norm of the vertical perimeter of any measurable subset of the $3$-dimensional Heisenberg group $\mathbb{H}$ is at most a universal constant multiple of the (Heisenberg) perimeter of the subset. We show that this…

Metric Geometry · Mathematics 2021-04-30 Assaf Naor , Robert Young

For an analytic function $f$ defined on the unit disk $|z|<1$, let $\Delta(r,f)$ denote the area of the image of the subdisk $|z|<r$ under $f$, where $0<r\le 1$. In 1990, Yamashita conjectured that $\Delta(r,z/f)\le \pi r^2$ for convex…

Complex Variables · Mathematics 2015-04-02 S. K. Sahoo , N. L. Sharma

In this paper, we prove the corona theorem for $M(D(\mu_k))$ in two different ways, where $\mu_k = \sum_{i=1}^k a_i \delta_{\zeta_i}$. Then we prove that the Bass stable rank of $M(D(\mu_k))$ is one.

Functional Analysis · Mathematics 2014-01-29 Shuaibing Luo

Recently the author has presented a new approach to solving extremal problems of geometric function theory. It involves the Bers isomorphism theorem for Teichmuller spaces of punctured Riemann surfaces. We show here that this approach,…

Complex Variables · Mathematics 2020-04-01 Samuel L. Krushkal

For a domain bounded by homogeneous subsets of a Lipschitz graph, we show the Corona Theorem is affirmative.

Complex Variables · Mathematics 2010-02-17 Brady Max NewDelman

We characterize the algebra $H^\infty \circ L_{m}$, where $m$ is a point of the maximal ideal space of $H^\infty$ with nontrivial Gleason part $P(m)$ and $L_{m} : \mathbb{D}\to P(m)$ is the coordinate Hoffman map. In particular, it is shown…

Functional Analysis · Mathematics 2022-02-01 Daniel Suárez

We establish triviality of some holomorphic Banach vector bundles on the maximal ideal space of the Banach algebra of bounded holomorphic functions on the unit disk with pointwise multiplication and supremum norm. We apply the result to the…

Complex Variables · Mathematics 2011-04-12 Alexander Brudnyi

The Cluster Value Theorem is known for being a weak version of the classical Corona Theorem. Given a Banach space $X$, we study the Cluster Value Problem for the ball algebra $A_u(B_X)$, the Banach algebra of all uniformly continuous…

Functional Analysis · Mathematics 2017-05-17 Daniel Carando , Daniel Galicer , Santiago Muro , Pablo Sevilla-Peris

Let $(M,F)$ be a $C^\infty$ Finsler manifold, $p\geq 1$ a real number, $k$ a positive integer and $H_k^p (M)$ a certain Sobolev space determined by a Finsler structure $F$. Here, it is shown that the set of all real $C^{\infty}$ functions…

Differential Geometry · Mathematics 2013-10-31 Behroz Bidabad , Alireza Shahi

In this paper, we obtain estimates for the solutions to the classical B{\'e}zout equation that are analogous to Carleson's solution to the corona theorem for the bounded analytic functions on the open unit disk. As an application, we extend…

Classical Analysis and ODEs · Mathematics 2022-05-03 Emmanuel Fricain , Andreas Hartmann , Ross William T. , Dan Timotin

We establish a regularity result for optimal sets of the isoperimetric problem with double density under mild ($\alpha$-)H\"older regularity assumptions on the density functions. Our main Theorem improves some previous results and allows to…

Analysis of PDEs · Mathematics 2023-08-15 Lisa Beck , Eleonora Cinti , Christian Seis

Here, a natural extension of Sobolev spaces is defined for a Finsler structure $F$ and it is shown that the set of all real $C^{\infty}$ functions with compact support on a forward geodesically complete Finsler manifold $(M, F)$, is dense…

Differential Geometry · Mathematics 2020-02-21 Behroz Bidabad , Alireza Shahi

We prove existence and uniqueness of a solution of the Dirichlet problem for separately $(\alpha, \beta)$ - harmonic functions on the unit polydisc $\mathbb D^n$ with boundary data in $C(\mathbb T^n)$ using $(\alpha, \beta)$ - Poisson…

Complex Variables · Mathematics 2023-05-19 Jelena Gajic , Milos Arsenovic , Miodrag Mateljevic

Given a complex domain $\Omega$ and analytic functions $\varphi_1,\ldots,\varphi_n : \Omega \to \mathbb{D}$, we give geometric conditions for $H^\infty(\Omega)$ to be generated by functions of the form $g \circ \varphi_k$, $g \in…

Complex Variables · Mathematics 2017-03-22 Michael A. Dritschel , Daniel Estévez , Dmitry Yakubovich

We prove a Corona type theorem with bounds for the Sarason algebra $H^\infty+C$ and determine its spectral characteristics. We also determine the Bass, the dense, and the topological stable ranks of $H^\infty+C$.

Complex Variables · Mathematics 2010-12-06 Raymond Mortini , Brett D. Wick

We establish basic results of complex function theory within certain algebras of holomorphic functions on coverings of Stein manifolds (such as algebras of Bohr's holomorphic almost periodic functions on tube domains or algebras of all…

Complex Variables · Mathematics 2013-10-01 A. Brudnyi , D. Kinzebulatov

This survey shows how, for the Nevanlinna class N of the unit disc, one can define and often characterize the analogues of well-known objects and properties related to the algebra of bounded analytic functions $ H^\infty$: interpolating…

Complex Variables · Mathematics 2019-11-07 Xavier Massaneda , Pascal J. Thomas

A space $X$ is said to be $\kappa$-resolvable (resp. almost $\kappa$-resolvable) if it contains $\kappa$ dense sets that are pairwise disjoint (resp. almost disjoint over the ideal of nowhere dense subsets). $X$ is maximally resolvable iff…

General Topology · Mathematics 2007-05-23 Istvan Juhasz , Lajos Soukup , Zoltan Szentmiklossy

Let $X$ be a compact metric space and let $|A|$ denote the cardinality of a set $A$. We prove that if $f\colon X\to X$ is a homeomorphism and $|X|=\infty$ then for all $\delta>0$ there is $A\subset X$ such that $|A|=4$ and for all $k\in Z$…

Dynamical Systems · Mathematics 2014-04-03 Alfonso Artigue