Structure constants of diagonal reduction algebras of gl type
  We describe, in terms of generators and relations, the reduction algebra, related to the diagonal embedding of the Lie algebra $\gl_n$ into $\gl_n\oplus\gl_n$. Its representation theory is related to the theory of decompositions of tensor products of $\gl_n$-modules. 
S. Khoroshkin and O. Ogievetsky
math.RA math-ph math.MP math.RT