Projections onto separable $C^*$-subalgebras of a $W^*$-algebra

Weak Projections onto a Braided Hopf Algebra

We show that, under some mild conditions, a bialgebra in an abelian and coabelian braided monoidal category has a weak projection onto a formally smooth (as a coalgebra) sub-bialgebra with antipode; see Theorem 1.12. In the second part of the paper we prove that bialgebras with weak projections are cross product bialgebras; see Theorem 2.12. In the particular case when the bialgebra A is cocomm...

Projections from a von Neumann algebra onto a subalgebra

— This paper is mainly devoted to the following question : let M, N be Von Neumann algebras with M C N. If there is a completely bounded projection P : N -^ M, is there automatically a contractive projection P : N -^ M? We give an affirmative answer with the only restriction that M is assumed semi-finite. The main point is the isometric identification of the complex interpolation space (AO, Ai ...

On subalgebras of an evolution algebra of a "chicken" population

We consider an evolution algebra which corresponds to a bisexual population with a set of females partitioned into finitely many different types and the males having only one type. For such algebras in terms of its structure constants we calculate right and plenary periods of generator elements. Some results on subalgebras of EACP and ideals on low-dimensional EACP are obtained.

C*-algebra generated by projections

The universal C*-algebra generated by n projections has been described. As an immediate corollary one obtains structure theorem for a pair of projections and the solution to an associated index problem. This puts the study of a pair of projections in the proper perspective of noncommutative geometry. keyword: Index problem, crossed product, Fredholm module, pair of projections. MSC 46L87.

Existence of an Algebra Norm on Certain Subalgebras of C(X)