Search results for "bound"

Algebras of unbounded operators and physical applications: a survey

2009

After a historical introduction on the standard algebraic approach to quantum mechanics of large systems we review the basic mathematical aspects of the algebras of unbounded operators. After that we discuss in some details their relevance in physical applications.

Pseudodifferential Analysis on Manifolds with Boundary — a Comparison of b-Calculus and Cone Algebra

2001

We establish a relation between two different approaches to a complete pseudodifferential analysis of totally characteristic or Fuchs type operators on compact manifolds with boundary respectively conical singularities: Melrose’s (overblown) b-calculus and Schulze’s cone algebra. Though quite different in their definition, we show that these two pseudodifferential calculi basically contain the same operators.

Continuous *-homomorphisms of Banach Partial *-algebras

2007

We continue the study of Banach partial *-algebras, in particular the question of the interplay between *-homomorphisms and biweights. Two special types of objects are introduced, namely, relatively bounded biweights and Banach partial *-algebras satisfying a certain Condition (S), which behave in a more regular way. We also present a systematic construction of Banach partial *-algebras of this type and exhibit several examples.

Representations of modules over a*-algebra and related seminorms

2008

Representations of a module X over a � -algebra A# are considered and some related seminorms are constructed and studied, with the aim of finding bounded � -representations of A #.

Banach elements and spectrum in Banach quasi *-algebras

2006

A normal Banach quasi -algebra (X;A_0) has a distinguished Banach - algebra X_b consisting of bounded elements of X. The latter -algebra is shown to coincide with the set of elements of X having fi nite spectral radius. If the family P(X) of bounded invariant positive sesquilinear forms on X contains suffi ciently many elements then the Banach -algebra of bounded elements can be characterized via a C -seminorm defi ned by the elements of P(X).

O* - Dynamical Systems and * - Derivations of Unbounded Operator Algebras

1999

A spatial theory is developed for * - derivations of an algebra of unbounded operators, in terms of the concept of O*-dynamical systems. Three notions of spatiality emerge, depending on the nature of the corresponding generator. Special emphasis is put on O*-dynamical systems generated by one-parameter groups of *-automorphisms and their *-derivations.

STOP 13: Inland dune field near Daugavpils, East-Latvian Lowland

2014

The Global Boundary Stratotype Section and Point (GSSP) for the base of the Pliensbachian Stage (Lower Jurassic), Wine Haven, Yorkshire, UK

2006

14 pages; International audience; Following votes by the Pliensbachian Working Group, the Jurassic Subcommission and the International Commission on Stratigraphy, IUGS ratified the proposed Global Boundary Stratotype Section and Point (GSSP) for the base of the Pliensbachian Stage (Lower Jurassic) at the base of bed 73b in the Wine Haven section, Robin Hood's Bay, Yorkshire Coast, UK. This level contains the characteristic ammonite association Bifericeras donovani Dommergues and Meister and Apoderoceras sp. Complementary data include: a) Strontium-isotope stratigraphy, based on analysis of belemnites which yield a calcite 87Sr/86Sr ratio for the boundary level of 0.707425 and data supportin…

Thuoux and Saint-Pierre d’Argençon Sections (Subalpine Basin, Southeastern France): Case Studies of Ammonite Biostratigraphy for the Potential Candid…

2014

The Thuoux and Saint-Pierre d’Argencon sections (Subalpine Basin, southeastern France) display a thick silty–clayey sedimentation with abundant and diversified ammonite faunas, free of detectable hiatuses. The Callovian–Oxfordian boundary is biostratigraphically located between the Lamberti and the Mariae zones or, more precisely, between the Lamberti Subzone (paucicostatum horizon) and the Scarburgense Subzone (thuouxensis horizon). The mixing of Boreal–Sub-Boreal Cardioceratinae and Sub-Mediterranean–Tethyan Hecticoceratinae, Peltoceratinae, and Perisphinctinae in this basin allows reliable worldwide correlations that enhance the choice of the Thuoux and Saint-Pierre d’Argencon sections a…

Proposal for the Thuoux section as a candidate for the GSSP of the base of the Oxfordian stage.

2012

20 pages; International audience; The Thuoux section, located in South-Eastern Basin of France (coordinates: 44°30'55"E; 5°42'25"N), is a section that satisfies numerous demanding criteria as reference section (GSSP) for the base of the Oxfordian stage. Sedimentation was continuous in that the abundant ammonitic fauna yields no detectable hiatuses. The stratigraphic boundary is located between the Lamberti Zone and the Mariae Zone or more precisely between the Paucicostatum horizon (MARCHAND, 1979) and the Thuouxensis horizon (FORTWENGLER & MARCHAND, 1994a). In this section, there is a perfect mixing bet-ween Boreal ammonites (Cardioceratinae) whose species are used as stratigraphic markers…