Let Γ1 and Γ2 be Bieberbach groups contained in the full isometry group G of Rn. We provethat if the compact flat manifolds Γ1\Rn and Γ2\Rn are strongly isospectral, then the Bieberbachgroups Γ1 and Γ2 are representation ...

In this paper we establish a close relationship between the spherical functions of the n-dimensional sphere $S^n\simeq\SO(n+1)/\SO(n)$ and the spherical functions of the n-dimensional real projective space $P^n(\mathbb{R ...

This paper deals with naturally reductive pseudo-Riemannian 2- step nilpotent Lie groups for which the metric is invariant under a left action. The case of nondegenerate center is characterized as follows. The simply ...

Coverings in the representation theory of algebras were introduced for the Auslander-Reiten quiver of a representation-finite algebra in [Ch. Riedtmann, Algebren, Darstellungsköcher, Überlagerungen und zurüch, Comment. ...

We develop further the techniques presented in a previous article (M. Mombelli. Abh. Math. Semin. Univ. Hamb. 82 (2012), 173–192), to study bimodule categories over the representation categories of arbitrary finite-dimensional ...

This study analyzes the impact of iconic representations of quantity (objects and images) and arbitrary representations (spoken number words) on the performance of 3-, 3.5- and 4-year-old children when building collections ...

Until a couple of years ago, the only known examples of Lie groups admitting left-invariant metrics with negative Ricci curvature were either solvable or semisimple.We use a general construction from a previous article of ...

In this work, we consider a family of Gelfand pairs (KnN, N) (inshort (K, N) ) where Nis a two step nilpotent Lie group, and Kis the group oforthogonal automorphisms ofN. This family has a nice analytic property: almos ...

Let 2+S4 denote the double cover of S4 corresponding to the element in H2(S4, Z/2Z) where transpositions lift to elements of order 2 and the product of two disjoint transpositions to elements of order 4. Given an elliptic ...

Let G be a compact connected semisimple Lie group, let K be a closed subgroup of G, let Γ be a finite subgroup of G, and let τ be a finitedimensional representation of K. For π in the unitary dual G of G, denote by nΓ(π) ...