The zero locus of the infinitesimal invariant
  Let {\nu} be a normal function on a complex manifold X. The infinitesimal invariant of {\nu} has a well-defined zero locus inside the tangent bundle TX. When X is quasi-projective, and {\nu} is admissible, we show that this zero locus is constructible in the Zariski topology. 
Greg Pearlstein, Christian Schnell
math.AG