Isomorphic vector-valued Banach-Stone theorems for subspaces

Al-Halees Hasan; Fleming Richard J.: Isomorphic vector-valued Banach-Stone theorems for subspaces. In: Acta scientiarum mathematicarum, (81) 1-2. pp. 189-214. (2015)

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Given a Banach space X, we define the number Ao(X) = inf d(X2,P(2)), where the infimum is taken over all two-dimensional subspaces X2 of X. Here, d(M, N) means the Banach-Mazur distance between Banach spaces M,N defined by d(M, N) = inf{||T||||T_1|| : T: M N is an isomorphism}. We establish some facts about Ao and then consider applications to Banach-Stone type theorems for isomorphisms on continuous, vector-valued function spaces. If Q,K are locally compact Hausdorff spaces, and X,Y are Banach spaces for which both Ao(X*) and AQ(Y*) are greater than one, it has been shown that if T is an isomorphism from CQ(Q. E) onto Co(K, Y) with ||T||||T~1 1| sufficiently small, then Q and K are homeomorphic, a generalization of the Banach-Stone Theorem for isometries. We examine such results for subspaces of these spaces. A closed subspace M of C'oiQ, X) is said to be a Co(Q)-module if it is closed under multiplication by functions in Co(<5). If M and N are Co(Q), Gb(X)-modules, respectively, then with assumptions similar to those mentioned above, we are able to obtain results in which the homeomorphism is between the strong boundaries of N and M. In this case, the strong boundaries are the subsets of K and Q, respectively, upon which the functions in N and M have nonzero values. We also obtain a new theorem concerning isometries.

Mű típusa: Cikk, tanulmány, mű
Befoglaló folyóirat/kiadvány címe: Acta scientiarum mathematicarum
Dátum: 2015
Kötet: 81
Szám: 1-2
ISSN: 0001-6969
Oldalak: pp. 189-214
Nyelv: angol
Kiadó: Bolyai Institute, University of Szeged
Kiadás helye: Szeged
Hivatalos webcím (URL): http://www.acta.hu
Befoglaló mű URL: http://acta.bibl.u-szeged.hu/38692/
DOI: 10.14232/actasm-014-255-x
Kulcsszavak: Matematika
Megjegyzések: Bibliogr.: p. 213-214. ; összefoglalás angol nyelven
Szakterület: 01. Természettudományok
01. Természettudományok > 01.01. Matematika
Feltöltés dátuma: 2016. okt. 17. 10:36
Utolsó módosítás: 2026. feb. 24. 11:13
URI: http://acta.bibl.u-szeged.hu/id/eprint/35202
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