Selected topics in Cohomology of non-arithmetical groups (algebras) and open questions

Selected topic in the cohomology of non-arithmetical groups algebras and grouppal structures are chosen and reviewed. The basics formalisms are recalled. The comparisons between the different approaches are proposed, from which new open questions arise; in particular, the application of the method of satellites to the study of non- arithmetical grouppal structures is evidentiated to request the definition of new structures in the calculation of the irreducible characters