2 papers
math.CA2026
On singular integrals with non-negative kernels in the Heisenberg group
Vasileios Chousionis, Sean Li, Lingxiao Zhang
In this paper we revisit nonnegative kernels in the first Heisenberg group $\He$, and in particular we further study the family $$K_α(x,y,z)= \frac{|z|^{α/2}}{\|(x,y,z)\|_{H}^{α…
math.CA2025
Singular integrals on intrinsic graphs in step 2 Carnot groups
Vasileios Chousionis, Sean Li, Lingxiao Zhang
We study singular integral operators induced by Calderón-Zygmund kernels in any step- Carnot group . We show that if such an operator satisfies some natural cancell…