Displaying similar documents to “Contact transformation of a presymplectic form with quasi-Sasakian structure.”

Quasi-linear maps

D. J. Grubb (2008)

Fundamenta Mathematicae


A quasi-linear map from a continuous function space C(X) is one which is linear on each singly generated subalgebra. We show that the collection of quasi-linear functionals has a Banach space pre-dual with a natural order. We then investigate quasi-linear maps between two continuous function spaces, classifying them in terms of generalized image transformations.

Versatile asymmetrical tight extensions

Olivier Olela Otafudu, Zechariah Mushaandja (2017)

Topological Algebra and its Applications


We show that the image of a q-hyperconvex quasi-metric space under a retraction is q-hyperconvex. Furthermore, we establish that quasi-tightness and quasi-essentiality of an extension of a T0-quasi-metric space are equivalent.

Quasi-lines and their degenerations

Laurent Bonavero, Andreas Höring (2007)

Annali della Scuola Normale Superiore di Pisa - Classe di Scienze


In this paper we study the structure of manifolds that contain a quasi-line and give some evidence towards the fact that the irreducible components of degenerations of the quasi-line should determine the Mori cone. We show that the minimality with respect to a quasi-line yields strong restrictions on fibre space structures of the manifold.

On Quasi-Normality of Two-Sided Multiplication

Amouch, M. (2009)

Serdica Mathematical Journal


2000 Mathematics Subject Classification: 47B47, 47B10, 47A30. In this note, we characterize quasi-normality of two-sided multiplication, restricted to a norm ideal and we extend this result, to an important class which contains all quasi-normal operators. Also we give some applications of this result.