Minimal Geodesics and Nilpotent Fundamental Groups
  Hedlund constructed Riemannian metrics on n-tori, $n \geq 3$ for which minimal geodesics are very rare. In this paper we construct similar examples for every nilpotent fundamental group. These examples show that Bangert's existence results of minimal geodesics are optimal for nilpotent fundamental groups. 
Bernd Ammann (University Freiburg and CUNY New York)