We study the deformation theory of morphisms of properads and props thereby
extending to a non-linear framework Quillen's deformation theory for
commutative rings. The associated chain complex is endowed with a Lie algebra
up to homotopy structure. Its Maurer-Cartan elements correspond to deformed
structures, which allows us to give a geometric interpretation of these
results.
To do so, we endow the category of prop(erad)s with a model category
structure. We provide a complete study of models for prop(erad)s. A new
effective method to make minimal models explicit, that extends Koszul duality
theory, is introduced and the associated notion is called homotopy Koszul.
As a corollary, we obtain the (co)homology theories of (al)gebras over a
prop(erad) and of homotopy (al)gebras as well. Their underlying chain complex
is endowed with a canonical Lie algebra up to homotopy structure in general and
a Lie algebra structure only in the Koszul case. In particular, we explicit the
deformation complex of morphisms from the properad of associative bialgebras.
For any minimal model of this properad, the boundary map of this chain complex
is shown to be the one defined by Gerstenhaber and Schack. As a corollary, this
paper provides a complete proof of the existence of a Lie algebra up to
homotopy structure on the Gerstenhaber-Schack bicomplex associated to the
deformations of associative bialgebras.Comment: Version 4 : Statement about the properad of (non-commutative)
Frobenius bialgebras fixed in Section 4. [82 pages
