Due to the absolute value involved, the first absolute central moment can be divided into two complementary filters: a positive deviation ep and a negative deviation en. Both ep and en can be used separately to highlight edges, lines, line endings, corners and junctions in images. Furthermore, the recovered edge information can be usefully combined to obtain additional information that would no...

After discussing some basic facts about generalized module maps, we use the representation theory of the algebra Ba(E) of adjointable operators on a Hilbert B–module E to show that the quotient of the group of generalized unitaries on E and its normal subgroup of unitaries on E is a subgroup of the group of automorphisms of the range ideal BE of E in B. We determine the kernel of the canonical ...

In the framework of locally covariant quantum field theory, a theory is described as a functor from a category of spacetimes to a category of ∗-algebras. It is proposed that the global gauge group of such a theory can be identified as the group of automorphisms of the defining functor. Consequently, multiplets of fields may be identified at the functorial level. It is shown that locally covaria...

Let K be a field with char(K) 6= 2. Let us fix an algebraic closure Ka of K. Let us put Gal(K) := Aut(Ka/K). If X is an abelian variety of positive dimension over Ka then we write End(X) for the ring of all its Ka-endomorphisms and End (X) for the corresponding (semisimple finite-dimensional) Q-algebra End(X)⊗ Q. We write EndK(X) for the ring of all K-endomorphisms of X and End 0 K(X) for the c...

The affine group schemes of automorphisms the multilinear r -fold cross products on finite-dimensional vectors spaces over fields characteristic not two are determined. Gradings by abelian groups these structures, that correspond to morphisms from diagonalizable into automorphisms, completely classified, up isomorphism.

An action of Z by automorphisms of a k-graph induces an action of Z by automorphisms of the corresponding k-graph C∗-algebra. We show how to construct a (k + l)-graph whose C∗-algebra coincides with the crossed product of the original k-graph C∗-algebra by Z. We then investigate the structure of the crossed-product C∗-algebra.

An action of Z by automorphisms of a k-graph induces an action of Z by automorphisms of the corresponding k-graph C∗-algebra. We show how to construct a (k + l)-graph whose C∗-algebra coincides with the crossed product of the original k-graph algebra by Z. We then investigate the structure of the crossed-product C∗-algebra.