Abstract We study left-invariant conformal Killing 2- or 3-forms on simply connected 2-step nilpotent Riemannian Lie groups. show that if the center of group is dimension greater than equal to 4, then every such form automatically coclosed (i.e. it a form). In addition, we prove only groups with at most 3 and admitting non-coclosed are following: The Heisenberg their trivial 1-dimensional exten...

Let G be a semi-simple Lie group with finite center and S ⊂ G a semigroup with intS 6= Ø . A closed subgroup L ⊂ G is said to be S -admissible if S is transitive in G/L . In [10] it was proved that a necessary condition for L to be S -admissible is that its action in B (S) is minimal and contractive where B (S) is the flag manifold associated with S , as in [9]. It is proved here, under an addi...

during the past few years, the iranian system of education and research in law has received severe changes, which have seriously damaged this system, and consequently have led to the decline of the iranian legal system. some such changes are not limited to law; rather, they are present in other fields of human sciences. this can be partially due to university instructors (e.g., how they are rec...