Countability properties of the ideal space of a Banach algebra and d-algebras

1997 ◽  
Vol 46 (3) ◽  
pp. 451-464
Author(s):  
Ferdinand Beckhoff
Keyword(s):  
1967 ◽  
Vol 45 (10) ◽  
pp. 3241-3245 ◽  
Author(s):  
P. A. Simard

A method is presented in the scheme of the boson approximation such that the antisymmetry between the quasi-particles is introduced naturally. Based on the transcription of the quasi-particle into the ideal space, the method enables one to give a unified description of the anharmonic corrections in the even–even and odd spherical nuclei.


2010 ◽  
Vol 8 (2) ◽  
pp. 167-179 ◽  
Author(s):  
R. L. Johnson ◽  
C. R. Warner

H1(R) is a Banach algebra which has better mapping properties under singular integrals thanL1(R) . We show that its approximate identity sequences are unbounded by constructing one unbounded approximate identity sequence {vn}. We introduce a Banach algebraQthat properly lies betweenH1andL1, and use it to show thatc(1 + lnn) ≤ ||vn||H1≤Cn1/2. We identify the maximal ideal space ofH1and give the appropriate version of Wiener's Tauberian theorem.


2022 ◽  
Author(s):  
René Hernández

The book explores the manuscripts written, read, and studied by Franciscan friars from the thirteenth to the fifteenth centuries in Northern Italy, and specifically Padua, assessing four key aspects: ideal, space, form and readership. The ideal is studied through the regulations that determined what manuscripts should aim for. Space refers to the development and role of Franciscan libraries. The form is revealed by the assessment of the physical configuration of a set of representative manuscripts read, written, and manufactured by the friars. Finally, the study of the readership shows how Franciscans were skilled readers who employed certain forms of the manuscript as a portable, personal library, and as a tool for learning and pastoral care. By comparing the book collections of Padua’s reformed and unreformed medieval Franciscan libraries for the first time, this study reveals new features of the ground-breaking cultural agency of medieval friars.


1959 ◽  
Vol 11 ◽  
pp. 297-310 ◽  
Author(s):  
Bernard R. Gelbaum

This paper is concerned with a generalization of some recent theorems of Hausner (1) and Johnson (4; 5). Their result can be summarized as follows: Let G be a locally compact abelian group, A a commutative Banach algebra, B1 = Bl(G,A) the (commutative Banach) algebra of A-valued, Bochner integrable junctions on G, 3m1the maximal ideal space of A, m2the maximal ideal space of L1(G) [the [commutative Banach] algebra of complex-valued, Haar integrable functions on G, m3the maximal ideal space of B1. Then m3and the Cartesian product m1 X m2are homeomorphic when the spaces mi, i = 1, 2, 3, are given their weak* topologies. Furthermore, the association between m3and m1 X m2is such as to permit a description of any epimorphism E3: B1 → B1/m3 in terms of related epimorphisms E1: A → A/M1 and E2:L1(G) → Ll(G)/M2, where M1 is in mi i = 1, 2, 3.


2003 ◽  
Vol 2003 (13) ◽  
pp. 817-825
Author(s):  
Terje Hõim ◽  
D. A. Robbins

LetXbe a Banach module over the commutative Banach algebraAwith maximal ideal spaceΔ. We show that there is a norm-decreasing representation ofXas a space of bounded sections in a Banach bundleπ:ℰ→Δ, whose fibers are quotient modules ofX. There is also a representation ofM(X), the space of multipliersT:A→X, as a space of sections in the same bundle, but this representation may not be continuous. These sectional representations subsume results of various authors over the past three decades.


1999 ◽  
Vol 51 (1) ◽  
pp. 147-163 ◽  
Author(s):  
Daniel Suárez

AbstractLet m be a point of the maximal ideal space of H∞ with nontrivial Gleason part P(m). If Lm : D → P(m) is the Hoffman map, we show that H∞ ° Lm is a closed subalgebra of H∞. We characterize the points m for which Lm is a homeomorphism in terms of interpolating sequences, and we show that in this case H∞ ° Lm coincides with H∞. Also, if Im is the ideal of functions in H∞ that identically vanish on P(m), we estimate the distance of any f ϵ H∞ to Im.


2019 ◽  
Vol 46 (5) ◽  
pp. 689-701 ◽  
Author(s):  
Jens Dorland ◽  
Christian Clausen ◽  
Michael Søgaard Jørgensen

Abstract Some see universities as a possible source of solutions to enable a sustainable transition and overcome societal challenges. Findings from three multisite case studies of Desis Labs, FabLabs, and Science Shops shed light on how universities can help empower communities and solve societal challenges locally. Adopting a sociotechnical and flat relational perspective inspired by science and technology studies (STS), we focus on the material and spatial aspects of how these spaces are configured, thereby ensuring practical relevance for policy makers and practitioners. Applying an analytical generalization methodology, we condense the qualitative data into a typology of three ideal space-types (i.e. affording, mediating, and impact-oriented) that represent specific configurations of actors, researchers, students, communities, spaces, infrastructure, equipment, facilitators, etc. The ideal space-types empower communities in different ways, require different resources to create and operate, and translate differently into specific local contexts.


1976 ◽  
Vol 28 (1) ◽  
pp. 42-49 ◽  
Author(s):  
B. V. Limaye

Let A be a commutative real Banach algebra with unit, and MA its maximal ideal space. The existence of the Silov boundary SA for A was established in [5] by resorting to the complexification of A. We give here an intrinsic proof of this result which exhibits the close connection between the absolute values and the real parts of ‘functions’ in A (Theorem 1.3).


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