A congruence modulo four in real Schubert calculus Academic Article uri icon


  • © De Gruyter 2016. We establish a congruence modulo four in the real Schubert calculus on the Grassmannian of m-planes in 2m-space. This congruence holds for fibers of the Wronski map and a generalization to what we call symmetric Schubert problems. This strengthens the usual congruence modulo two for numbers of real solutions to geometric problems. It also gives examples of geometric problems given by fibers of a map whose topological degree is zero but here each fiber contains real points.

author list (cited authors)

  • Hein, N., Sottile, F., & Zelenko, I.

citation count

  • 6

publication date

  • February 2014