摘要:

Certain classes of associative rings are characterized as finite subdirect products of specialized prime rings. These characterizations depend on results about Λ-classes and tight extensions, concepts that were fist introduced by Olson, Le Row and Hey man.

ISSN:1607-3606    

DOI:10.1080/16073606.1999.9632066

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

An affine motion of special type was developed in non-RiemannianK*-spaces by Takano [5]. He called such a motion an affine motion with contra field. The same concept was extended to Finsler spaces by Misra and Meher [1]. Later, the same authors [2] studied CA-motion in a projective symmetric Finsler space. An affine motion satisfying the condition υi(j)= ρδij, where ρ(x, x) is a non-zero scalar function, is called affine motion with contra field or briefly CA-motion. Recently the present author [4] has discussed projective motion in Finsler spaceFn. The purpose of this paper is to study affine and projective motions with contra field in Finsler spaces. The notations of Rund [3] are used in the sequel.

ISSN:1607-3606    

DOI:10.1080/16073606.1999.9632067

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

In this note we provide an elementary proof of the following: every automorphismSofL∞is of the formSf=foSzfor allfεL∞. As a first corollary we prove that if there exists a linear isometryTof a linear subspaceAofL∞containingH∞onto such a subspaceB, thenTcan be written as a weighted composition map, namely,Tf= α (foSz) for allfεA, where α εB, |α(λ)| = 1 for all λ in the unit circle andSis an automorphism ofL∞induced byT.As a straightforward consequence, we obtain a description of the linear isometries betweenDouglas algebras.As a second corollary we show that every linear bijectionTofL∞ontoL∞which preserves non-vanishing functions can also be written as a weighted composition map.

ISSN:1607-3606    

DOI:10.1080/16073606.1999.9632068

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

AS shown by Macneille, any distributive nearlattice A has a canonical distributive lattice extension A” that contains A as a hereditary subalgebra. Here, we consider distributive nearlattices A equipped with a binary residuation operation—that, essentially, models the implication connective of Intuitionistic Propositional Logic without the exchange and contraction rules. These form both a category and a quasivariety of algebras. We show that the canonical distributive lattice extension of a such a ‘distributive residuation nearlattice’ AMaybe enriched with a residuation operation which extends that of A and which behaves well with respect to morphisms. We also show that the lattices of relative congruences of A and A° are isomorphic, so that second order properties such as subdirect irreducibility and simplicity are preserved by the extension.

ISSN:1607-3606    

DOI:10.1080/16073606.1999.9632069

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Measure theoretic conditional expectation is used to construct certain operator spaces. The conditional expectation induces a Hilbert module structure on these spaces. Application is made of Kasparov's theorem to examine certain multiplier and compact operator algebras associated with the module structure. This examination is related to the now classic results on characterizations of conditional expectation type operators.

ISSN:1607-3606    

DOI:10.1080/16073606.1999.9632070

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

By using ordinary differential equations in Banach spaces, a topological degree for strict set contractions is defined and furthermore some new fixed point theorems are obtained. The degree is then proved to be the well-known Leray-Schauder degree for completely continuous operators and finally it is used to compute the Leray-Schauder degree for completely continuous operators with gradient forms.

ISSN:1607-3606    

DOI:10.1080/16073606.1999.9632071

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

LetHbe a Hopf algebra acting on a ringA, and letAHdenote the invariant subring ofA.It is shown that ifHis semisimple andAis a finitely generated projective rightAH—module then IdAH= IdA= Id(A#H). Moreover, ifAis a left and right noetherian ring with gl.dimA< infin;, it is deduced that gl.dimA. = gl.dimA.

ISSN:1607-3606    

DOI:10.1080/16073606.1999.9632072

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The aim of this paper is to continue the study of some topological properties weaker thanS-closed, this time via a local point of view. We show that every focally countablyS-closed km-perfect space is extremally disconnected as well as that every locally rc-Lindelöf mildly Hausdorff space is δ-extremally disconnected.

ISSN:1607-3606    

DOI:10.1080/16073606.1999.9632073

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

In this paper the ideas of a large and a small radical class of not necessarily associative rings and algebras are developed further and we explore these ideas in the case of alternative rings, right Lie rings and Jordan rings.

ISSN:1607-3606    

DOI:10.1080/16073606.1999.9632074

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Following a lead given by I.W. Alderton, it is shown that the MacNeille completion and the universal initial completion coincide for the categories of zero-dimensional fuzzy T0-topological spaces, T0-fuzzy closure spaces, 2T0-fuzzy bitopological spaces, andT1-fuzzy topological spaces and that these turn out to be respectively the categories of zero-dimensional fuzzy topological spaces, fuzzy closure spaces, fussy bitopological spaces, and fuzzyR0topological spaces.

ISSN:1607-3606    

DOI:10.1080/16073606.1999.9632075

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor