2 articles
Gowers norm
The Gowers norm, or Gowers uniformity norm, is a measure of how far a function on a finite group deviates from a low-degree polynomial phase, introduced by Timothy Gowers in 1998.
Nilsystem
A nilsystem is a dynamical system on a compact nilmanifold G/Γ of a nilpotent Lie group, with translation dynamics; nilsystems are the characteristic factors in multiple ergodic averages.