[EN] In this paper we study Prym varieties and their moduli space using the well-known
techniques of the infinite Grassmannian. There are three main results of this paper: a new
definition of the BKP hierarchy over an arbitrary base field (that generalizes the classical
one over C); a characterization of Prym varieties in terms of dynamical systems, and explicit
equations for the moduli space of (certain) Prym varieties. For all of these problems the
language of the infinite Grassmannian, in its algebro-geometric version, allows us to deal
with these problems from the same point of view.
