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Related papers: On the extension of Whitney ultrajets

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We characterize the validity of the Whitney extension theorem in the ultradifferentiable Roumieu setting with controlled loss of regularity. Specifically, we show that in the main Theorem 1.3 of [15] condition (1.3) can be dropped.…

Classical Analysis and ODEs · Mathematics 2022-12-29 Armin Rainer , Gerhard Schindl

We prove a version of Whitney's extension theorem in the ultradifferentiable Beurling setting with controlled loss of regularity. As a by-product we show the existence of continuous linear extension operators on certain spaces of Whitney…

Classical Analysis and ODEs · Mathematics 2021-01-08 Armin Rainer

We revisit Whitney's extension theorem in the ultradifferentiable Roumieu setting. Based on the description of ultradifferentiable classes by weight matrices, we extend results on how growth constraints on Whitney jets on arbitrary compact…

Classical Analysis and ODEs · Mathematics 2017-11-29 Armin Rainer , Gerhard Schindl

We prove a variant of the standard Whitney extension theorem for $\mathcal C^m(\mathbb R^n)$, in which the norm of the extension operator has polynomial growth in $n$ for fixed $m$.

Classical Analysis and ODEs · Mathematics 2015-08-10 Alan Chang

We prove an extension theorem for ultraholomorphic classes defined by so-called Braun-Meise-Taylor weight functions and transfer the proofs from the single weight sequence case from V. Thilliez [28] to the weight function setting. We are…

Functional Analysis · Mathematics 2018-05-25 Javier Jiménez-Garrido , Javier Sanz , Gerhard Schindl

In this article we study the validity of the Whitney $C^1$ extension property for horizontal curves in sub-Riemannian manifolds endowed with 1-jets that satisfy a first-order Taylor expansion compatibility condition. We first consider the…

Metric Geometry · Mathematics 2018-12-21 Ludovic Sacchelli , Mario Sigalotti

For a compact set, we characterize the existence of a linear extension operator E for the space of Whitney jets without loss of derivatives, that is, E satisfies the best possible continuity estimates: The supremum of all partial…

Functional Analysis · Mathematics 2013-08-21 Leonhard Frerick , Enrique Jordá , Jochen Wengenroth

Given a compact of ${\bf R}^n$, there is always a doubling measure having it as its support. We use this fact to construct an integral operator that extends differentiable functions defined on any compact set of ${\bf R}^n$ to the whole of…

Classical Analysis and ODEs · Mathematics 2007-05-23 Jaume Gudayol

Let $k\in\mathbb{N}_0\cup\{\infty\}$. According to Whitney's extension theorem, each real-valued Whitney $k$-Jet on a closed subset $A\subseteq\mathbb{R}^n$ can be extended to a $C^k$-function on $\mathbb{R}^n$. Based on Whitney's original…

Functional Analysis · Mathematics 2023-07-18 Johanna Jakob

We consider several general conditions for integrability of two Roumieu ultradistributions and prove their equivalence. The discussed sequential conditions are based on two classes of approximate units and allow one to introduce sequential…

Functional Analysis · Mathematics 2020-03-03 Svetlana Mincheva-Kaminska

The aim of this work is to generalize the ultraholomorphic extension theorems from V. Thilliez in the weight sequence setting and from the authors in the weight function setting (of Roumieu type) to a mixed framework. Such mixed results…

Complex Variables · Mathematics 2022-12-29 Javier Jiménez-Garrido , Javier Sanz , Gerhard Schindl

We give a proof of the o-minimal version of the Whitney Extension Theorem simplified as compared to the original ones. A new simplifying ingredient is a definable variant of Urysohn's lemma for class $\mathcal{C}^q$ (see Section 3).

Logic · Mathematics 2026-03-17 Beata Kocel-Cynk , Wiesław Pawłucki , Anna Valette

Let $C$ be a subset of $\mathbb{R}^n$ (not necessarily convex), $f:C\to\mathbb{R}$ be a function, and $G:C\to\mathbb{R}^n$ be a uniformly continuous function, with modulus of continuity $\omega$. We provide a necessary and sufficient…

Classical Analysis and ODEs · Mathematics 2016-10-11 Daniel Azagra , Carlos Mudarra

We survey ultradifferentiable extension theorems, i.e., quantitative versions of Whitney's classical extension theorem, with special emphasis on the existence of continuous linear extension operators. The focus is on Denjoy-Carleman classes…

Functional Analysis · Mathematics 2022-01-03 Armin Rainer

We prove sectorial extension theorems for ultraholomorphic function classes of Beurling type defined by weight functions with a controlled loss of regularity. The proofs are based on a reduction lemma, due to the second author, which allows…

Functional Analysis · Mathematics 2022-12-29 David Nicolas Nenning , Armin Rainer , Gerhard Schindl

We prove the computability of a version of Whitney Extension, when the input is suitably represented. More specifically, if $F \subseteq \mathbb{R}^n$ is a closed set represented so that the distance function $x \mapsto d(x,F)$ can be…

Logic · Mathematics 2026-04-07 Andrea Brun , Guido Gherardi , Alberto Marcone

The Whitney extension theorem is a classical result in analysis giving a necessary and sufficient condition for a function defined on a closed set to be extendable to the whole space with a given class of regularity. It has been adapted to…

Metric Geometry · Mathematics 2018-03-16 Nicolas Juillet , Mario Sigalotti

In this paper we are concerned with the space of tempered ultrahyperfunctions corresponding to a proper open convex cone. A holomorphic extension theorem (the version of the celebrated edge of the wedge theorem) will be given for this…

Functional Analysis · Mathematics 2009-10-28 Daniel H. T. Franco

A hyperplane arrangement is said to satisfy the ``Riemann hypothesis'' if all roots of its characteristic polynomial have the same real part. This property was conjectured by Postnikov and Stanley for certain families of arrangements which…

Combinatorics · Mathematics 2016-09-07 Christos A. Athanasiadis

The Whitney near extension problem for finite sets in $\mathbb R^d,\, d\geq 2$ asks the following: Let $\phi:E\to \mathbb R^d$ be a near distortion on a finite set $E\subset \mathbb R^d$ with certain geometry. How to decide whether $\phi$…

Classical Analysis and ODEs · Mathematics 2023-03-30 S. B. Damelin
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