We first prove, in the context of ∞-categories and using Goodwillie's
calculus of functors, that various definitions of the cotangent complex of a
map of E∞-ring spectra that exist in the literature are equivalent. We
then prove the following theorem: if R is an E∞-ring spectrum and
f:G→Pic(R) is a map of E∞-groups, then the cotangent
complex over R of the Thom E∞-R-algebra of f is equivalent to the
smash product of Mf and the connective spectrum associated to G.Comment: 19 page