Eric Riedl

Associate Professor


Ph.D., Harvard University, 2015
B.S., University of Notre Dame, 2010

Research Group

Algebra and Algebraic Geometry

Research Area

Algebraic Geometry


Research Interests

I am an algebraic geometer, interested in birational geometry, rational curves, hypersurfaces, and rationality problems. Specifically, I am interested in studying the geometry of hypersurfaces in projective space by studying the rational curves lying on them.

A motivating theme in algebraic geometry is that the positivity or negativity of the canonical bundle controls the geometry of the variety. There are many important, open conjectures in this vein like the Lang Conjectures and Manin's Conjecture, and an important test case for these conjectures are hypersurfaces in projective space. I study questions such as:

  • As the degree of a very general hypersurface in Pn changes, what happens to the dimensions of its spaces of rational curves? There are very precise conjectures about how they should behave, but there remain many important cases where this is unproven (such as Clemens' Conjecture for quintic threefolds).
  • Do very general hypersurfaces in Pn with degree d < n contain many rational surfaces? It is suspected that for n large and d near to n, the answer is no, which would provide an example of a rationally connected variety that is not unirational. This would resolve a longstanding open question in birational geometry. An important tool in understanding this question is to understand the normal bundles of these curves, which control the local structure of these moduli spaces.
  • What do the entire curves on a very general large-degree hypersurface look like? As d gets to about 2n, there are expected (by the Kobayashi Conjecture) to be none, making these hypersurfaces hyperbolic. However, the current bounds known are multiply exponential in n.

Selected Publications

  • Riedl, Eric and Yang, David Kontsevich spaces of rational curves on Fano hypersurfaces, J. Reine Angew. Math. (to appear).
  • Coskun, Izzet and Riedl, Eric Normal bundles of rational curves in projective space Mathematische Zeitschrift (to appear). arXiv:1607.06149
  • Coskun, Izzet and Riedl, Eric Normal bundles of rational curves on complete intersections (accepted to Communications in Contemporary Mathematics)
  • Riedl, Eric and Woolf, Matthew Rational curves on complete intersections in positive characteristic (accepted to Journal of Algebra) arXiv:1609.05958
  • Riedl, Eric and Yang, David, Applications of a grassmannian technique in hypersurfaces arXiv:1806.02364 (submitted for publication)

Phone: 574-631-8370
Fax: 574-631-6579
Office: 142 Hayes-Healy Bldg