On the Combinatorics of the Universal Enveloping Algebra Uh(sl2)
  We study using combinatorial methods the structural coefficients of the formal homogeneous universal enveloping algebra Uh(sl2) of the special linear algebra sl2 over a field of characteristic zero. We provide explicit formulae for the product of generic elements in Uh(sl2), and construct combinatorial objects giving flesh to these formulae. 
Rafael Diaz, Edward Salamanca
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