On the second cohomology of nilpotent orbits in exceptional Lie algebras
  In this paper we consider non-compact non-complex exceptional Lie algebras, and compute the dimensions of the second cohomology groups for most of the nilpotent orbits. For the rest of cases of nilpotent orbits, which are not covered in the above computations, we obtain upper bounds for the dimensions of the second cohomology groups. 
Pralay Chatterjee and Chandan Maity
math.GR math.AT math.RT