W*-algebras and invariant functionals
W*-algebras on Banach spaces
Weak almost Periodicity on C*-Algebras.
Weak approximation by positive maps on -algebras
Weak c*-Hopf algebras: the coassociative symmetry of non-integral dimensions
By allowing the coproduct to be non-unital and weakening the counit and antipode axioms of a C*-Hopf algebra too, we obtain a selfdual set of axioms describing a coassociative quantum group, that we call a weak C*-Hopf algebra, which is sufficiently general to describe the symmetries of essentially arbitrary fusion rules. It is the same structure that can be obtained by replacing the multiplicative unitary of Baaj and Skandalis with a partial isometry. The algebraic properties, the existence of...
Weak compactness in the dual of a C*-algebra is determined commutatively.
Weak continuity of holomorphic automorphisms in JB-triples.
Weak multiplier Hopf algebras. Preliminaries, motivation and basic examples
Let G be a finite group. Consider the algebra A of all complex functions on G (with pointwise product). Define a coproduct Δ on A by Δ(f)(p,q) = f(pq) where f ∈ A and p,q ∈ G. Then (A,Δ) is a Hopf algebra. If G is only a groupoid, so that the product of two elements is not always defined, one still can consider A and define Δ(f)(p,q) as above when pq is defined. If we let Δ(f)(p,q) = 0 otherwise, we still get a coproduct on A, but Δ(1) will no longer be the identity in A ⊗ A. The pair (A,Δ)...
Weak Riesz groups
Weak star and bounded weak star continuity of Banach algebra products
Weak type estimates associated to Burkholder's martingale inequality.
Weakly Compact Operators on Jordan Triples.
When is a quantum space not a group?
We give a survey of techniques from quantum group theory which can be used to show that some quantum spaces (objects of the category dual to the category of C*-algebras) do not admit any quantum group structure. We also provide a number of examples which include some very well known quantum spaces. Our tools include several purely quantum group theoretical results as well as study of existence of characters and traces on C*-algebras describing the considered quantum spaces as well as properties...
When is there a discontinuous homomorphism from L¹(G)?
Let A be an A*-algebra with enveloping C*-algebra C*(A). We show that, under certain conditions, a homomorphism from C*(A) into a Banach algebra is continuous if and only if its restriction to A is continuous. We apply this result to the question in the title.
WKB approximation in noncommutative gravity.