这个测度由匈牙利数学家 Alfréd Haar 于1933年发明 。哈尔测度用于数学分析，数论，群论，表示论，估计理论和遍历理论的很多方面。
英语百科
Haar measure 哈尔测度
In mathematical analysis, the Haar measure assigns an "invariant volume" to subsets of locally compact topological groups, consequently defining an integral for functions on those groups.
This measure was introduced by Alfréd Haar in 1933. Haar measures are used in many parts of analysis, number theory, group theory, representation theory, statistics, and ergodic theory.