3 papers
math.DG2024
On some relations between the Perimeter, the Area and the Visual Angle of a Convex Set
Joaquim Bruna, Julià Cufí, Agustí Reventós
We establish some relations between the perimeter, the area and the visual angle of a planar compact convex set. Our first result states that Crofton's formula is the unique univer…
math.HO2023
A historical review of the Cauchy-Riemann equations and the Cauchy Theorem
Julià Cufí, Agustí Reventós
In this article we take a historical tour through the Cauchy-Riemann equations and their relationship with Cauchy's theorem on the independence with respect to the path of the inte…
math.FA2011
Characterizing abelian admissible groups
Joaquim Bruna, Julià Cufí, Hartmut Führ +1
By definition, admissible matrix groups are those that give rise to a wavelet-type inversion formula. This paper investigates necessary and sufficient admissibility conditions for…