On quasiregular values
On quasiregular values
滨苍-笔别谤蝉辞苍听罢补濒办听
A quasiregular (QR) map is a Sobolev map f: 鈩鈦 鈫 鈩鈦 satisfying the distortion inequality |Df(x)|鈦 鈮 K det(Df(x)) at almost every x, where K 鈮 1 is a constant. QR maps form a higher-dimensional class of maps with many similar properties to holomorphic maps, such as continuity, openness, discreteness, and versions of the Liouville, Picard and Montel theorems. In this talk, we consider a generalization of the distortion inequality of the form |Df(x)|鈦 鈮 K det(Df(x)) + 危(x)|f(x) - y|, where 危 is a locally L岬-integrable function for p > 1 and y 鈭 鈩鈦 is a fixed point. We show that this condition yields counterparts to many fundamental properties of QR maps at the single point y, including single-value versions of openness, discreteness, and the Liouville theorem. Joint work with Jani Onninen.