The Hirota equation over finite fields. Algebro-geometric approach and   multisoliton solutions
  We consider the Hirota equation (the discrete analog of the generalized Toda system) over a finite field. We present the general algebro-geometric method of construction of solutions of the equation. As an example we construct analogs of the multisoliton solutions for which the wave functions and the $\tau$-function can be found using rational functions. Within the class of multisoliton solutions we isolate generalized breather-type solutions which have no direct counterparts in the complex field case. 
Adam Doliwa, Mariusz Bialecki, Pawel Klimczewski