1. DENSITY PROPERTIES OF CERTAIN GROUP ACTIONS AND JOINING RIGIDITY OF SOME SMOOTH SINGULAR FLOWS Open Access Author: Dong, Changguang Title: DENSITY PROPERTIES OF CERTAIN GROUP ACTIONS AND JOINING RIGIDITY OF SOME SMOOTH SINGULAR FLOWS Graduate Program: Mathematics Keywords: group actionrigidityRatner propertydensity File: Download Dissertation-dong.pdf Committee Members: Federico Juan Rodriguez Hertz, Dissertation Advisor/Co-AdvisorFederico Juan Rodriguez Hertz, Committee Chair/Co-ChairYakov B Pesin, Committee MemberZhiren Wang, Committee MemberWilliam Nielsen Brandt, Outside Member