In this paper we analyze some aspects of the question of using methods from model theory to study structures of functional analysis. By a well known result of P. Lindström, one cannot extend the expressive power of first order logic and yet preserve its most outstanding model theoretic characteristics (e.g., compactness and the Löwenheim-Skolem theorem). However, one may consider extending the ...

The maximality of certain symplectic subgroups of unitary groups PSUn(K), n ≥ 4, (K any field admitting a non–trivial involutory automorphism) belonging to the class C5 of Aschbacher is proved. Furthermore some related geometry in the case n = 4 and K finite is investigated. Mathematics Subject Classification (2002): 20G40, 20G28

We consider Arveson’s problem on the maximality of subdiagonal algebras. We prove that a subdiagonal algebra is maximal if it is invariant under the modular group of a faithful normal state which is preserved by the conditional expectation associated with the subdiagonal algebra.

Positive modalities in S4, S5 and systems in their vicinity are investigated in terms of categorial proof theory. Coherence and maximality results are demonstrated, and connections with mixed distributive laws and Frobenius algebras are exhibited. Mathematics Subject Classification (2000), Primary : 03B45, 03G30, 18C15, Secondary : 03F07, 03C05, 08C05, 18A15, 18A40, 18B10, 18C10, 18C20

We study a class of [0, 1]-valued logics for continuous metric structures. The main result of the paper is maximality theorem that characterizes these logics in terms of a model-theoretic property, namely, an extension of the omitting types theorem to uncountable languages.

Let |V | 6= v. The goal of the present article is to derive analytically d-closed, hyper-globally symmetric, hyperbolic vectors. We show that Y is not greater than Φ. So in [26], the authors classified contravariant random variables. In future work, we plan to address questions of maximality as well as negativity.

Generalised convexity is revisited from a geometrical point of view. A substitute to the subdifferential is proposed. Then generalised monotonicity is considered. A representation of generalised monotone maps allows to obtain a symmetry between maps and their inverses. Finally, maximality of generalised monotone maps is analysed.

We are concerned with surjectivity of perturbations of maximal monotone operators in non-reflexive Banach spaces. While in a reflexive setting, a classical surjectivity result due to Rockafellar gives a necessary and sufficient condition to maximal monotonicity, in a nonreflexive space we characterize maximality using a “enlarged” version of the duality mapping, introduced previously by Gossez....

Since the fall of parity in electroweak interactions the discrete transformations of parity, charge conjugation and time reversal are under close scrutiny for any sign of deviation from maximality where symmetry breaking seems to be complete (like P violation in β decay) and for any sign of symmetry breaking when this has not yet been observed (like T violation in

An efficient algorithm is developed that identifies all independencies implied by the topology of a Baye­ sian network. Its correctness and maximality stems from the soundness and completeness of d­ separation with respect to probability theory. The al­ gorithm runs in time 0 (IE I ) where E is the number of edges in the network.