Agrachev, Andrei A.2013-02-282013-02-282013-01-10https://openscience.sissa.it/handle/1963/651024 pagesWe study homological invariants of smooth families of real quadratic forms as a step towards a "Lagrange multipliers rule in the large" that intends to describe topology of smooth vector functions in terms of scalar Lagrange functions.enPreprintMAT/03 GEOMETRIA