Chiral unitary theory: Application to nuclear problems

In this talk we briefly describe some basic elements of chiral perturbation theory, xPT, and how the implementation of unitarity and other novel elements lead to a better expansion of the T-matrix for meson-meson and meson-baryon interactions. Applications are then done to the ππ interaction in nuclear matter in the scalar and vector channels, antikaons in nuclei and K− atoms, and how the φ meson properties are changed in a nuclear medium.