52 citations · 367 across the 81 of their papers we have counts for
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An integralgeometric approach to Dorronsoro estimates
Tuomas Orponen
A theorem of Dorronsoro from 1985 quantifies the fact that a Lipschitz function can be approximated by affine functions almost everywhere,…
Riesz transform and vertical oscillation in the Heisenberg group
Katrin Fässler, Tuomas Orponen
We study the -boundedness of the -dimensional (Heisenberg) Riesz transform on intrinsic Lipschitz graphs in the first Heisenberg group . Inspired by the notio…
The local symmetry condition in the Heisenberg group
Tuomas Orponen
I propose an analogue in the first Heisenberg group of David and Semmes' local symmetry condition (LSC). For closed -regular sets , I show tha…
Semmes surfaces and intrinsic Lipschitz graphs in the Heisenberg group
Katrin Fässler, Tuomas Orponen, Séverine Rigot
A Semmes surface in the Heisenberg group is a closed set that is upper Ahlfors-regular with codimension one and satisfies the following condition, referred to as Condition B. E…