## Applications of twisted technology

Christoph Thiele

University of California, Los Angeles

March 29, 2017

Recently we proved with Durcik, Kovac, Skreb variational estimates providing sharp quantitative norm convergence results for bilinear ergodic averages with respect to two commuting transformations. The proof uses so called twisted technology developed in recent years for estimating bi-parameter paraproducts. Another application of the technique is to cancellation results for simplex Hilbert transforms.