4 papers
Local set approximation: Mattila-Vuorinen type sets, Reifenberg type sets, and tangent sets
Matthew Badger, Stephen Lewis
We investigate the interplay between the local and asymptotic geometry of a set and the geometry of model sets $\mathcal{S} \subset \mathcal{P}(\mathbb{R…
Singular points of Hölder asymptotically optimally doubling measures
Stephen Lewis
We consider the question of how the doubling characteristic of a measure determines the regularity of its support. The question was considered by David, Kenig, and Toro for codimen…
Supercharacters, symmetric functions in noncommuting variables, and related Hopf algebras
Marcelo Aguiar, Carlos Andre, Carolina Benedetti +25
We identify two seemingly disparate structures: supercharacters, a useful way of doing Fourier analysis on the group of unipotent uppertriangular matrices with coefficients in a fi…
Nonzero coefficients in restrictions and tensor products of supercharacters of
Stephen Lewis, Nathaniel Thiem
The standard supercharacter theory of the finite unipotent upper-triangular matrices gives rise to a beautiful combinatorics based on set partitions. As with the represent…