Purely quantum superadditivity of classical capacities of quantum multiple access channels.
We are studying classical capacities of quantum memoryless multiaccess channels in geometric terms and we are revealing a break of additivity of the Holevo-like capacity. This effect is a purely quantum mechanical one, since, as we point out, the capacity regions of all classical memoryless multiaccess channels are additive. It is the first such effect revealed in the field of classical information transmission via quantum channels.
This paper surveys bocses, quasi-hereditary algebras and their relationship which was established in a recent result by Koenig, Ovsienko, and the author. Particular emphasis is placed on applications of this result to the representation type of the category filtered by standard modules for a quasi-hereditary algebra. In this direction, joint work with Thiel is presented showing that the subcategory of modules filtered by Weyl modules for tame Schur algebras is of finite representation type. The paper also includes a new proof for the classification of quasi-hereditary algebras with two simple modules, a result originally obtained by Membrillo-Hern\'andez.