Ivan Panin

Abstract: Let R be a regular local ring containing the field of rational numbers. Let K be the field of fractions of R, let Q be a quadratic form over R and let u be a unit in R. We will discuss the following result: If the equation Q = u has a solution over K then it has a solution over R. This theorem solves a rather old problem in the theory of quadratic forms. The solution is based on a moving lemma for algebraic cobordism proved by M.Levine and F.Morel.   

Here are some directions to Northeastern University. Lake Hall can be best accessed from the entrance on the corner of Greenleaf Street and Leon Street.