B\"acklund transformations for the rational Lagrange chain
  We consider a long--range homogeneous chain where the local variables are the generators of the direct sum of $N$ $\mathfrak{e}(3)$ interacting Lagrange tops. We call this classical integrable model rational ``Lagrange chain'' showing how one can obtain it starting from $\mathfrak{su}(2)$ rational Gaudin models. Moreover we construct one- and two--point integrable maps (B\"acklund transformations). 
Fabio Musso, Matteo Petrera, Orlando Ragnisco, Giovanni Satta