Research output: Contribution to journal › Article
Subspaces of C∞ invariant under the differentiation. / Aleman, A.; Baranov, A.; Belov, Y.
In: Journal of Functional Analysis, Vol. 268, No. 8, 2015, p. 2421-2439.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Subspaces of C∞ invariant under the differentiation
AU - Aleman, A.
AU - Baranov, A.
AU - Belov, Y.
PY - 2015
Y1 - 2015
N2 - © 2015 Elsevier Inc.Let L be a proper differentiation invariant subspace of C∞(a, b) such that the restriction operator ddx|L has a discrete spectrum Λ (counting with multiplicities). We prove that L is spanned by functions vanishing outside some closed interval I⊂(a, b) and monomial exponentials xkeλx corresponding to Λ if its density is strictly less than the critical value |I|2π, and moreover, we show that the result is not necessarily true when the density of Λ 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.
AB - © 2015 Elsevier Inc.Let L be a proper differentiation invariant subspace of C∞(a, b) such that the restriction operator ddx|L has a discrete spectrum Λ (counting with multiplicities). We prove that L is spanned by functions vanishing outside some closed interval I⊂(a, b) and monomial exponentials xkeλx corresponding to Λ if its density is strictly less than the critical value |I|2π, and moreover, we show that the result is not necessarily true when the density of Λ 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.
U2 - 10.1016/j.jfa.2015.01.002
DO - 10.1016/j.jfa.2015.01.002
M3 - Article
VL - 268
SP - 2421
EP - 2439
JO - Journal of Functional Analysis
JF - Journal of Functional Analysis
SN - 0022-1236
IS - 8
ER -
ID: 3988655