Shiing-Shen Chern developed methods connecting curvature, differential geometry and topological invariants. His joint work with James Simons constructs secondary characteristic forms from connections.[ref]
Characteristic forms and geometric invariants by Shiing-Shen Chern and James Simons. Original byline and introduction
The key relation expresses a characteristic curvature form as an exterior derivative on an appropriate total space. Its primitive carries geometric information beyond the original cohomology class. The resulting Chern-Simons forms connects local differential forms with global invariants and later applications in mathematical physics.[ref]
