Characters and inner forms of a quasi-split group over
Let be a locally compact group. Let be the left translation in , given by . We characterize (undre a mild set-theoretical hypothesis) the functions such that the map from into is scalarly measurable (i.e. for , is measurable). We show that it is the case when is measurable for each character , and if is compact, if and only if is Riemann-measurable. We show that is Borel measurable if and only if is left uniformly continuous.Some of the measure-theoretic tools used there...
Let be a metric space with a doubling measure, be a boundedly compact metric space and be a Lebesgue precise mapping whose upper gradient belongs to the Lorentz space , . Let be a set of measure zero. Then for -a.e. , where is the -dimensional Hausdorff measure and is the -codimensional Hausdorff measure. This property is closely related to the coarea formula and implies a version of the Eilenberg inequality. The result relies on estimates of Hausdorff content of level sets...