On the Product of Two (Totally) Minimal Topological Groups and the Three-Space-Problem.
On the properly discontinuous subgroups of affine motions.
On the Property P... of Locally Compact Groups
On the Proportionality of Covolumes of Discrete Subgroups.
On the regularity and rationality of certain elements of finite order in Lie groups.
On the representation of solutions of stochastic differential equations
On the representations of certain idempotent topological semigroups.
On the representations of unitarily induced from derived functor modules
On the rigidity of webs
Plane -webs have been studied a lot since their appearance at the turn of the 20th century. A rather recent and striking result for them is the theorem of Dufour, stating that the measurable conjugacies between 3-webs have to be analytic. Here, we show that even the set-theoretic conjugacies between two -webs, are analytic unless both webs are analytically parallelizable. Between two set-theoretically conjugate parallelizable -webs, however, there always exists a nonmeasurable conjugacy; still,...
On the -invariance property for -flows.
On the Saito-Kurokawa Lifting.
On the second order derivatives of convex functions on the Heisenberg group
In the euclidean setting the celebrated Aleksandrov-Busemann-Feller theorem states that convex functions are a.e. twice differentiable. In this paper we prove that a similar result holds in the Heisenberg group, by showing that every continuous –convex function belongs to the class of functions whose second order horizontal distributional derivatives are Radon measures. Together with a recent result by Ambrosio and Magnani, this proves the existence a.e. of second order horizontal derivatives for...
On the Segal-Shale-Weil Representations and Harmonic Polynomials.
On the set of orbits for a Borel subgroup.
On the S-Euclidean minimum of an ideal class
We show that the S-Euclidean minimum of an ideal class is a rational number, generalizing a result of Cerri. In the proof, we actually obtain a slight refinement of this and give some corollaries which explain the relationship of our results with Lenstra's notion of a norm-Euclidean ideal class and the conjecture of Barnes and Swinnerton-Dyer on quadratic forms. In particular, we resolve a conjecture of Lenstra except when the S-units have rank one. The proof is self-contained but uses ideas from...
On the Siegel-Weil Formula.
On the similarity between the Iwasawa projection and the diagonal part
On the singular support of distributions and Fourier transforms on symmetric spaces
On the size of quotients of function spaces on a topological group
For a non-precompact topological group G, we consider the space C(G) of bounded, continuous, scalar-valued functions on G with the supremum norm, together with the subspace LMC(G) of left multiplicatively continuous functions, the subspace LUC(G) of left norm continuous functions, and the subspace WAP(G) of weakly almost periodic functions. We establish that the quotient space LUC(G)/WAP(G) contains a linear isometric copy of , and that the quotient space C(G)/LMC(G) (and a fortiori C(G)/LUC(G))...
On the spectral radius in