Research output: Contribution to journal › Article › peer-review
Differentiation in the Branges spaces and embedding theorems. / Baranov, A. D.
In: Journal of Mathematical Sciences, Vol. 101, No. 2, 01.01.2000, p. 2881-2913.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Differentiation in the Branges spaces and embedding theorems
AU - Baranov, A. D.
PY - 2000/1/1
Y1 - 2000/1/1
N2 - The boundedness conditions for the differentiation operator in Hilbert spaces of entire functions (Branges spaces) and conditions under which the embedding K⊖ ∪ L2(μ) holds in spaces K⊖ associated with the Branges spaces ℋ(E) are studied. Measures μ such that the above embedding is isometric are of special interest. It turns out that the condition E′/E ∈ H∞(C+) is sufficient for the boundedness of the differentiation operator in ℋ(E). Under certain restrictions on E, this condition is also necessary. However, this fact fails in the general case, which is demonstrated by the counterexamples constructed in this paper. The convex structure of the set of measures μ such that the embedding KĖ/E ∪ L2(μ) is isometric (the set of such measures was described by de Branges) is considered. Some classes of measures that are extreme points in the set of Branges measures are distinguished. Examples of measures that are not extreme points are also given. Bibliography: 7 titles.
AB - The boundedness conditions for the differentiation operator in Hilbert spaces of entire functions (Branges spaces) and conditions under which the embedding K⊖ ∪ L2(μ) holds in spaces K⊖ associated with the Branges spaces ℋ(E) are studied. Measures μ such that the above embedding is isometric are of special interest. It turns out that the condition E′/E ∈ H∞(C+) is sufficient for the boundedness of the differentiation operator in ℋ(E). Under certain restrictions on E, this condition is also necessary. However, this fact fails in the general case, which is demonstrated by the counterexamples constructed in this paper. The convex structure of the set of measures μ such that the embedding KĖ/E ∪ L2(μ) is isometric (the set of such measures was described by de Branges) is considered. Some classes of measures that are extreme points in the set of Branges measures are distinguished. Examples of measures that are not extreme points are also given. Bibliography: 7 titles.
UR - http://www.scopus.com/inward/record.url?scp=0010465573&partnerID=8YFLogxK
U2 - 10.1007/BF02672176
DO - 10.1007/BF02672176
M3 - Article
AN - SCOPUS:0010465573
VL - 101
SP - 2881
EP - 2913
JO - Journal of Mathematical Sciences
JF - Journal of Mathematical Sciences
SN - 1072-3374
IS - 2
ER -
ID: 32721314