Corwin, Ivan
Seppäläinen, Timo
Shen, Hao
Funding for this research was provided by:
National Science Foundation (DMS-1306777, DMS-1208998)
Wisconsin Alumni Research Foundation
Clay Mathematics Institute
Institut Henri-Poincaré
David and Lucile Packard Foundation
Article History
Received: 26 November 2014
Accepted: 14 April 2015
First Online: 1 May 2015