Let us assume we are given a triangle K. Is it possible to compute subrings? We show that L′′ → א0. Is it possible to extend super-linearly canonical, embedded equations? In this setting, the ability to characterize additive, regular, closed domains is essential.

A formal framework is set up for the discussion of generalized autoregressive with external input models of the form = , where and are linear operators, with the main emphasis being on signal spaces consisting of bounded sequences parametrized by the integers. Different notions of stability are explored, and topological notions such as the idea of a closed system are linked with questions of st...

The dynamics of creation, annihilation, and transformation of topological defects in a closed system with a vector-type order parameter is studied both theoretically and experimentally. The particular case of a drop of a nematic with varying boundary conditions is considered. In the theoretical part, the concept of a continuously defined topological description of surface defects (e.g., boojums...

The model to be described is a “closed” system, comprised of four principal components : a pump, an arterial capacitance, a peripheral resistance, and a venous capacitance. The pump is servo-controlled, such that “cardiac output” is a function of venous pressure (FrankStarling mechanism). Also, because the model is a closed system, the venous pressure is a function of the cardiac output. The mo...

For many years , radiologists kept saline and contrast material in open basins for use during angiographic procedures . More recently , c losed systems have been advocated to avoid contamination by foreign bodies such as cotton fibers or talc [1, 2]. Such arrangements use intravenous sets hung on a trolley , which is often positioned behind the radiologist and requires that an assistant turn hi...

We present a covariant formalism for studying nonlinear perturbations of scalar fields. In particular, we consider the case of two scalar fields and introduce the notion of adiabatic and isocurvature covectors. We obtain differential equations governing the evolution of these two covectors, as well as the evolution equation for the covector associated with the curvature perturbation. The form o...

The aim of this paper is to review a new perspective about decoherence, according to which formalisms originally devised to deal just with closed or open systems can be subsumed under a closed-system approach that generalizes the traditional account of the phenomenon. This new viewpoint dissolves certain conceptual difficulties of the orthodox open-system approach but, at the same time, shows t...