We characterize affine mappings on the unit disk and on rectangles by module conditions. The main result generalizes the classic Schwarz lemma. As an application, we give a sufficient condition for a K-quasiconformal mapping on a Riemann surface to be a Teichmüller mapping.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-sm157-1-6, author = {Zhiguo Chen}, title = {Geometric characterization for affine mappings and Teichm\"uller mappings}, journal = {Studia Mathematica}, volume = {157}, year = {2003}, pages = {71-82}, zbl = {1020.30016}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm157-1-6} }
Zhiguo Chen. Geometric characterization for affine mappings and Teichmüller mappings. Studia Mathematica, Tome 157 (2003) pp. 71-82. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm157-1-6/