Tracker fields from nonminimally coupled theory

We extend the concept of quintessence to flat nonminimally coupled scalar-tensor theories of gravity. By means of Noether's symmetries for the cosmological pointlike Lagrangian L, it is possible to exhibit exact solutions for a class of models depending on a free parameter s. This parameter comes out in the relationship existing between the coupling F(φ) and the potential V(φ) because of such a symmetry for L. When inverse power-law potentials are taken into account, a whole family of exact solutions parametrized by such an s is proposed as a class of tracker fields, and some considerations are made about them.