Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Subspaces of C-infinity invariant under the differentiation

Aleman, Alexandru LU ; Baranov, Anton and Belov, Yurii (2015) In Journal of Functional Analysis 268(8). p.2421-2439
Abstract
Let L be a proper differentiation invariant subspace of C-infinity (a, b) such that the restriction operator d/dx vertical bar L has a discrete spectrum Lambda (counting with multiplicities). We prove that L is spanned by functions vanishing outside some closed interval I subset of (a, b) and monomial exponentials x(k)e(lambda x) corresponding to Lambda if its density is strictly less than the critical value vertical bar I vertical bar/2 pi, and moreover, we show that the result is not necessarily true when the density of Lambda equals the critical value. This answers a question posed by the first author and B. Korenblum. Finally, if the residual part of L is trivial, then L is spanned by the monomial exponentials it contains. (C) 2015... (More)
Let L be a proper differentiation invariant subspace of C-infinity (a, b) such that the restriction operator d/dx vertical bar L has a discrete spectrum Lambda (counting with multiplicities). We prove that L is spanned by functions vanishing outside some closed interval I subset of (a, b) and monomial exponentials x(k)e(lambda x) corresponding to Lambda if its density is strictly less than the critical value vertical bar I vertical bar/2 pi, and moreover, we show that the result is not necessarily true when the density of Lambda equals the critical value. This answers a question posed by the first author and B. Korenblum. Finally, if the residual part of L is trivial, then L is spanned by the monomial exponentials it contains. (C) 2015 Elsevier Inc. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Spectral synthesis, Entire functions, Paley-Wiener spaces, Invariant, subspaces
in
Journal of Functional Analysis
volume
268
issue
8
pages
2421 - 2439
publisher
Elsevier
external identifiers
  • wos:000351807700012
  • scopus:84924140534
ISSN
0022-1236
DOI
10.1016/j.jfa.2015.01.002
language
English
LU publication?
yes
id
e396f9f6-085f-4dd7-858e-588c877dd8bd (old id 5277723)
date added to LUP
2016-04-01 13:53:06
date last changed
2022-03-06 08:17:52
@article{e396f9f6-085f-4dd7-858e-588c877dd8bd,
  abstract     = {{Let L be a proper differentiation invariant subspace of C-infinity (a, b) such that the restriction operator d/dx vertical bar L has a discrete spectrum Lambda (counting with multiplicities). We prove that L is spanned by functions vanishing outside some closed interval I subset of (a, b) and monomial exponentials x(k)e(lambda x) corresponding to Lambda if its density is strictly less than the critical value vertical bar I vertical bar/2 pi, and moreover, we show that the result is not necessarily true when the density of Lambda equals the critical value. This answers a question posed by the first author and B. Korenblum. Finally, if the residual part of L is trivial, then L is spanned by the monomial exponentials it contains. (C) 2015 Elsevier Inc. All rights reserved.}},
  author       = {{Aleman, Alexandru and Baranov, Anton and Belov, Yurii}},
  issn         = {{0022-1236}},
  keywords     = {{Spectral synthesis; Entire functions; Paley-Wiener spaces; Invariant; subspaces}},
  language     = {{eng}},
  number       = {{8}},
  pages        = {{2421--2439}},
  publisher    = {{Elsevier}},
  series       = {{Journal of Functional Analysis}},
  title        = {{Subspaces of C-infinity invariant under the differentiation}},
  url          = {{http://dx.doi.org/10.1016/j.jfa.2015.01.002}},
  doi          = {{10.1016/j.jfa.2015.01.002}},
  volume       = {{268}},
  year         = {{2015}},
}