All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 20 Next

Displaying 381 – 400 of 444

Showing per page

Restricting the bi-equivariant spectral triple on quantum SU(2) to the Podleś spheres

Elmar Wagner (2011)

Banach Center Publications

It is shown that the isospectral bi-equivariant spectral triple on quantum SU(2) and the isospectral equivariant spectral triples on the Podleś spheres are related by restriction. In this approach, the equatorial Podleś sphere is distinguished because only in this case the restricted spectral triple admits an equivariant grading operator together with a real structure (up to infinitesimals of arbitrary high order). The real structure is expressed by the Tomita operator on quantum SU(2) and it is...

Restrictions of CP-semigroups to maximal commutative subalgebras

Franco Fagnola, Michael Skeide (2007)

Banach Center Publications

We give a necessary and sufficient criterion for a normal CP-map on a von Neumann algebra to admit a restriction to a maximal commutative subalgebra. We apply this result to give a far reaching generalization of Rebolledo's sufficient criterion for the Lindblad generator of a Markov semigroup on ℬ(G).

Results on Colombeau product of distributions

Blagovest Damyanov (1997)

Commentationes Mathematicae Universitatis Carolinae

The differential ℂ -algebra 𝒢 ( ℝ m ) of generalized functions of J.-F. Colombeau contains the space 𝒟 ' ( ℝ m ) of Schwartz distributions as a ℂ -vector subspace and has a notion of ‘association’ that is a faithful generalization of the weak equality in 𝒟 ' ( ℝ m ) . This is particularly useful for evaluation of certain products of distributions, as they are embedded in 𝒢 ( ℝ m ) , in terms of distributions again. In this paper we propose some results of that kind for the products of the widely used distributions x ± a and δ ( p ) ( x ) , with x in ℝ m ,...

Results on generalized models and singular products of distributions in the Colombeau algebra 𝒢 ( ℝ )

Blagovest Damyanov (2015)

Commentationes Mathematicae Universitatis Carolinae

Models of singularities given by discontinuous functions or distributions by means of generalized functions of Colombeau have proved useful in many problems posed by physical phenomena. In this paper, we introduce in a systematic way generalized functions that model singularities given by distributions with singular point support. Furthermore, we evaluate various products of such generalized models when the results admit associated distributions. The obtained results follow the idea of a well-known...

Résumé des résultats essentiels dans la théorie des produits tensoriels topologiques et des espaces nucléaires

Alexander Grothendieck (1952)

Annales de l'institut Fourier

L’auteur donne un résumé des résultats essentiels de son travail “Produits tensoriels topologiques et espaces nucléaires” (à paraître dans Memoirs of the Am. Math. Soc.), en essayant de faire ressortir les idées directrices. Soient E et F deux espaces localement convexes, on définit d’abord deux topologies naturelles sur E ⊗ F , qui donnent des complétés E ⊗ ^ F et E ^ ⊗ ^ F , qu’on explicite dans divers cas importants, et dont on élucide les propriétés algébrico-topologiques, notamment à l’égard de la notion de produit...

Reverse-Holder classes in the Orlicz spaces setting

E. Harboure, O. Salinas, B. Viviani (1998)

Studia Mathematica

In connection with the A ϕ classes of weights (see [K-T] and [B-K]), we study, in the context of Orlicz spaces, the corresponding reverse-Hölder classes R H ϕ . We prove that when ϕ is Δ 2 and has lower index greater than one, the class R H ϕ coincides with some reverse-Hölder class R H q , q > 1 . For more general ϕ we still get R H ϕ ⊂ A ∞ = ⋃ q > 1 R H q although the intersection of all these R H ϕ gives a proper subset of ⋂ q > 1 R H q .

Rich families and elementary submodels

Marek Cúth, Ondřej Kalenda (2014)

Open Mathematics

We compare two methods of proving separable reduction theorems in functional analysis - the method of rich families and the method of elementary submodels. We show that any result proved using rich families holds also when formulated with elementary submodels and the converse is true in spaces with fundamental minimal system and in spaces of density ℵ1. We do not know whether the converse is true in general. We apply our results to show that a projectional skeleton may be without loss of generality...

Currently displaying 381 – 400 of 444