Elliptic Ruijsenaars-Schneider model from the cotangent bundle over the   two-dimensional current group
  It is shown that the elliptic Ruijsenaars-Schneider model can be obtained from the cotangent bundle over the two-dimensional current group by means of the Hamiltonian reduction procedure. 
G.E.Arutyunov, S.A.Frolov and P.B.Medvedev