Instituto Nacional de Derechos Humanos

A quadratic family of integral two-torsion classes in a Huneke-Wiegand Koszul presentation

For every integer p>=8, we prove that an explicit integral Koszul presentation associated with a previously constructed Huneke-Wiegand family has a direct summand (Z/2)^q, where q=floor(((p-2)^2+3)/12). The classes are indexed by the strictly increasing nonnegative triples i<j