R. Harvey et Hb. Lawson, A THEORY OF CHARACTERISTIC CURRENTS ASSOCIATED WITH A SINGULAR CONNECTION, Bulletin, new series, of the American Mathematical Society, 31(1), 1994, pp. 54-63
This note announces a general construction of characteristic currents
for singular connections on a vector bundle. It develops, in particula
r, a Chem-Weil-Simons theory for smooth bundle maps alpha : E --> F wh
ich, for smooth connections on E and F, establishes formulas of the ty
pe phi = Res(phi)SIGMA(alpha) + dT. Here phi is a standard charactersi
tic form, Res(phi) is an associated smooth ''residue'' form computed c
anonically in terms of curvature, SIGMA(alpha) is a rectifiable curren
t depending only on the singular structure of alpha, and T is a canoni
cal, functorial transgression form with coefficients in L(loc)1. The t
heory encompasses such classical topics as: Poincare-Lelong Theory, Bo
tt-Chem Theory, Chem-Weil Theory, and formulas of Hopf. Applications i
nclude: a new proof of the Riemann-Roch Theorem for vector bundles ove
r algebraic curves, a C(infinity)-generalization of the Poincare-Lelon
g Formula, universal formulas for the Thom class as an equivariant cha
racteristic form (i.e., canonical formulas for a de Rham representativ
e of the Thom class of a bundle with connection), and a Differentiable
Riemann-Roch-Grothendieck Theorem at the level of forms and currents.
A variety of formulas relating geometry and characteristic classes ar
e deduced as direct consequences of the theory.