Natural projectors in tensor spaces.
Which invariants of a Galois -extension of local number fields (residue field of char , and Galois group ) determine the structure of the ideals in as modules over the group ring , the -adic integers? We consider this question within the context of elementary abelian extensions, though we also briefly consider cyclic extensions. For elementary abelian groups , we propose and study a new group (within the group ring where is the residue field) and its resulting ramification filtrations....
This is an introductory paper about our recent merge of a noncommutative de Finetti type result with representations of the infinite braid and symmetric group which allows us to derive factorization properties from symmetries. We explain some of the main ideas of this approach and work out a constructive procedure to use in applications. Finally we illustrate the method by applying it to the theory of group characters.
A new formula is established for the asymptotic expansion of a matrix integral with values in a finite-dimensional von Neumann algebra in terms of graphs on surfaces which are orientable or non-orientable.