Quasi-Lie Algebras and Quasi-Deformations. Algebraic Structures Associated with Twisted Derivations
This thesis introduces a new deformation scheme for Lie algebras, which we refer to as ?quasi-deformations? to clearly distinguish it from the classical Grothendieck-Schlessinger and Gers-tenhaber deformation schemes. The main difference is that quasi-deformations are not in gene-ral category-preserving, i.e., quasi-deforming a Lie algebra gives an object in the larger catego-ry of ?quasi-Lie alge