  We give a new short proof that the wheeled operad of unimodular Lie algebras
is Koszul and use this to explicitly construct its minimal resolution. A
representation of this resolution in a finite dimensional vector space V we
call a unimodular L-infinity algebra. Such a structure corresponds to a
homological vector field on V together with an invariant measure. We present
explicit formulae for homotopy transferred structures, define the deformation
complex and give a cohomological obstruction to the extension of an arbitrary
structure of finite dimensional L-infinity algebra to a structure of unimodular
L-infinity algebra.
