On the negative Pell equation

Zoom Meeting ID: 919 6497 4060
For password see the email or contact Pieter Moree (moree@mpim...).

How often does the ring of integers of a real quadratic field have a unit with norm -1? In 1995
Peter Stevenhagen proposed a precise conjectural asymptotic formula describing how many such real quadratic fields should be out there when counted by discriminant. I will discuss a joint upcoming work with Peter Koymans where we establish Stevenhagen's conjecture.