Composing concurrent objects

Adopting the object-oriented paradigm for the development of large and complex software systems offers several advantages, of which increased extensibility and reusability are the most prominent ones. The object-oriented model is also quite suitable for modelling concurrent systems. However, it appears that extensibility and reusability of concurrent applications is far from trivial. In addition, very little attention has been paid by the conventional object-oriented development methodologies to the analysis and design of\ud synchronisation constraints for concurrent objects.\ud To address these problems, in this thesis the framework of composition-filters, an extension to the object-oriented model, is adopted. An analysis is presented of the problems involved in reusing and extending concurrent objects, in particular the so-called inheritance anomalies. Based on this analysis, a set of criteria for effective extensible concurrent objectoriented\ud programming languages is formulated.\ud The thesis introduces techniques for the creation of concurrency and the synchronisation of concurrent activities, fully integrated within the (object-oriented) composition-filters model. Important properties of the proposed object model are: all objects are -potentially- active, intra-object concurrency is supported and synchronisation specifications are fully separated\ud from method implementations. The applicability and expressive power of the proposed technique are demonstrated, and it is shown how reusability and extensibility of concurrent objects are achieved

Scaled-free objects II

This work creates two categories of "array-weighted sets" for the purposes of constructing universal matrix-normed spaces and algebras. These universal objects have the analogous universal property to the free vector space, lifting maps completely bounded on a generation set to a completely bounded linear map of the matrix-normed space. Moreover, the universal matrix-normed algebra is used to prove the existence of a free product for matrix-normed algebras using algebraic methods.Comment: 46 pages. Version 4 fixed a few minor typos. Version 3 added matricial completion; fixed an arithmetic error in Example 3.5.10. Version 2 added a preliminaries section on weighted sets and matricial Banach spaces, incorporating much of "Matricial Banach spaces" in summary; fixed a domain issue in Lemma 3.3.2; simplified Examples 3.5.10 and 4.11; added more proofs to Sections 4 and

Topological objects in QCD

Topological excitations are prominent candidates for explaining nonperturbative effects in QCD like confinement. In these lectures, I cover both formal treatments and applications of topological objects. The typical phenomena like BPS bounds, topology, the semiclassical approximation and chiral fermions are introduced by virtue of kinks. Then I proceed in higher dimensions with magnetic monopoles and instantons and special emphasis on calorons. Analytical aspects are discussed and an overview over models based on these objects as well as lattice results is given.Comment: 28 pages, 17 figures; Lectures given at 45th Internationale Universitaetswochen fuer Theoretische Physik (International University School of Theoretical Physics): Conceptual and Numerical Challenges in Femto- and Peta-Scale Physics, Schladming, Styria, Austria, 24 Feb - 3 Mar 200

Betting on Quantum Objects

Dutch book arguments have been applied to beliefs about the outcomes of measurements of quantum systems, but not to beliefs about quantum objects prior to measurement. In this paper, we prove a quantum version of the probabilists' Dutch book theorem that applies to both sorts of beliefs: roughly, if ideal beliefs are given by vector states, all and only Born-rule probabilities avoid Dutch books. This theorem and associated results have implications for operational and realist interpretations of the logic of a Hilbert lattice. In the latter case, we show that the defenders of the eigenstate-value orthodoxy face a trilemma. Those who favor vague properties avoid the trilemma, admitting all and only those beliefs about quantum objects that avoid Dutch books.Comment: 26 pages, 3 figures, 1 table; improved operational semantics, results unchange