Kurt Vinhage of the University of Utah presents recent work on classifying higher-rank semisimple Lie group actions that have uniformly expanding and contracting directions, delivered at the Joint IAS/Princeton Groups and Dynamics Seminar. He frames the problem against Robert Zimmer's 1980s program, which proposed studying such actions after proving rigidity results about measurable cocycles associated to them. Vinhage walks through the structure of partially hyperbolic dynamics in this setting and reports joint progress with D. Damjanovic, R. Spatzier, and D. Xu toward a classification theorem. The talk assumes familiarity with Lie theory and ergodic theory, moving through technical results on rigidity and cocycle behavior rather than offering an introductory survey. It is a research-level seminar talk aimed at specialists in smooth dynamics and group actions, giving a clear picture of where the Zimmer program stands today and what tools are driving the current classification effort.