for every rational function ƒ with poles off K. In this note it is shown that any operator for which the spectrum is a spectral set has a nontrivial invariant subspace. In [6] von Neumann introduced the notion of spectral set and showed that if T has II T\\ = 1 then the closed unit disc, D"~, is a spectral set for T. For this reason any operator whose spectrum is a spectral set is called a von ...

In this work we discuss the notion of observable both quantum and classical from a new point of view. In classical mechanics, an observable is represented as a function (measurable, continuous or smooth), whereas in (von Neumann’s approach to) quantum physics, an observable is represented as a bonded selfadjoint operator on Hilbert space. We will show in part II of this work that there is a com...

we study topological von neumann regularity and principal von neumann regularity of banach algebras. our main objective is comparing these two types of banach algebras and some other known banach algebras with one another. in particular, we show that the class of topologically von neumann regular banach algebras contains all $c^*$-algebras, group algebras of compact abelian groups and cer...

abstract background von willebrand disease (vwd) is an autosomally inherited bleeding disorder with the prevalence of 1% based on population studies. the disease phenotype is due to quantitative and structural/functional defects in von willebrand factor (vwf) which is a glycoprotein with essential role as a carrier of fviii in circulation and also it serves the function as hemostasis regulator....

In this paper, we clarify the structure of the Stone spectrum of an arbitrary finite von Neumann algebra R of type In. The main tool for this investigation is a generalized notion of rank for projections in von Neumann algebras of this type.

In the present paper, we shall attempt to make a contribution to approximate analytical evaluation of the harmonic decomposition of an arbitrary continuous function. The basic assumption is that the class of functions that we investigate here, except the verification of Dirichlet's principles, is concurrently able to be expanded in Taylor's representation, over a particular interval of their do...

a 22 year-old woman presented with gradual visual loss in her right eye since 1990. medical and family histories were unremarkable. her visual acuity was 20/80 and 20/20 in right and left eyes respectively. slit lamp examination was quite normal with no relative afferent papillary defect.fundi of both eyes revealed subretinal lesion with optic nerve head involvement and subretinal fluid in papi...

The Random Particle Mesh (RPM) method used to simulate turbulence-induced broadband noise in several aeroacoustic applications is extended to realise isotropic turbulence spectra. With this method turbulent fluctuations are synthesised by filtering white noise with a Gaussian filter kernel that in turn gives a Gaussian spectrum. The Gaussian function is smooth and its derivatives and integrals ...