2014, Becher, Karim Johannes, Grimm, David, Van Geel, Jan

A recently found local-global principle for quadratic forms over function fields of curves over a complete discretely valued field is applied to the study of quadratic forms, sums of squares, and related field invariants.

2007, Netzer, Tim, Grimm, David, Schweighofer, Markus

2012, Becher, Karim Johannes, Grimm, David, Van Geel, Jan

A recently found local-global principle for quadratic forms over function fields of curves over a complete discrete valued field is applied to the study of quadratic forms, sums of squares, and related field invariants.

2011, Grimm, David

We study sums of squares in algebraic function fields over formally real fields, in particular the arithmetic properties of the field of constants that are necessary or sufficient for a small Pythagoras number of the function field.