61 citations · 217 across the 16 of their papers we have counts for
5 papers · 1 filter
Homeomorphisms of the Heisenberg group preserving BMO
Riikka Korte, Niko Marola, Olli Saari
We provide a new geometric proof of Reimann's theorem characterizing quasiconformal mappings as the ones preserving functions of bounded mean oscillation. While our proof is new al…
A characterization of BMO self-maps of a metric measure space
Juha Kinnunen, Riikka Korte, Niko Marola +1
This paper studies functions of bounded mean oscillation (BMO) on metric spaces equipped with a doubling measure. The main result gives characterizations for mappings that preserve…
Aspects of local to global results
Ritva Hurri-Syrjänen, Niko Marola, Antti V. Vähäkangas
We establish local to global results for a function space which is larger than the well known BMO space, and was also introduced by John and Nirenberg.
Poincaré inequalities in quasihyperbolic boundary condition domains
Ritva Hurri-Syrjänen, Niko Marola, Antti V. Vähäkangas
We study the validity of (q,p)-Poincaré inequalities, q<p, on domains in R^n which satisfy a quasihyperbolic boundary condition, i.e. domains whose quasihyperbolic metric satisfies…
Aspects of area formulas by way of Luzin, Radó, and Reichelderfer on metric measure spaces
Niko Marola, William P. Ziemer
We consider some measure-theoretic properties of functions belonging to a Sobolev-type class on metric measure spaces that admit a Poincaré inequality and are equipped with a doubl…