摘要:

A higher-order extension of the perturbed Simple Harmonic Oscillator is discussed. The differential equation is

ISSN:1607-3606    

DOI:10.1080/16073606.1992.9631669

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Motivated by some results and concepts from radical theory for abelian groups, we investigate the radical classesRof associative rings for which there is an infinite cardinal number α such that for every ring A and everyaεR(A)we haveaεR(B)for (i) some idealBof A with |B| < α, (ii) some accessible subringBof A with |B| < α Only the class {0} satisfies (i), while the classes other than {0} which satisfy (ii) are the classesDpof zerorings on divisible P-groups for setsPof primes. We also consider an analogous question for strict radical classes and subrings. Here the answer is much more complicated, and in fact undecidable in ZFC.

ISSN:1607-3606    

DOI:10.1080/16073606.1992.9631670

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In this paper we study the relationships among the exponential spectra of the cosets of an element of a Banach algebra in some quotient Banach algebras. These relationships are necessary to be studied since the spectra and exponential spectra do not always coincide. This is anextensionof some work done by Laura Burlando [1] on the relationships among the spectra of the cosets of an element of a Banach algebra in some quotient algebras.

ISSN:1607-3606    

DOI:10.1080/16073606.1992.9631671

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

It is well known that the square root of a product of two positive elements exists in an Archimedean, uniformly complete semiprime f-algebra. In particular, if the f-algebra is unital, then the square root of any positive element exists. It is natural to ask whether the square root of every element exits in the complexification of such an f-algebra. In this note we show that the root does not exist in general. Some conditions for the existence of the root are given.

ISSN:1607-3606    

DOI:10.1080/16073606.1992.9631672

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The spectral mapping theorem is used to establish the approximation method for functions of normal operators in Hilbert spaces. The application of the method for approximating an inverse leads to an iterative procedure similar to the Chebyshev iterative technique in linear algebra. A numerical example is given to illustrate the method.

ISSN:1607-3606    

DOI:10.1080/16073606.1992.9631673

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

We study the set of points of a topological spaceXat which a multifunctionF: X → Yis interior. This paper also deals with the valuation of the Borel class of this set. The necessary examples and counterexamples are provided.

ISSN:1607-3606    

DOI:10.1080/16073606.1992.9631674

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The differential operator

ISSN:1607-3606    

DOI:10.1080/16073606.1992.9631675

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:1607-3606    

DOI:10.1080/16073606.1992.9631676

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:1607-3606    

DOI:10.1080/16073606.1992.9631668

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor