  Parity-violating and time-reversal conserving (PVTC) and parity-violating and
time-reversal-violating (PVTV) forces in nuclei form only a tiny component of
the total interaction between nucleons. The study of these tiny forces can
nevertheless be of extreme interest because they allow to obtain information on
fundamental symmetries using nuclear systems. The PVTC interaction derives from
the weak interaction between the quarks inside nucleons and nuclei and the
study of PVTC effects opens a window on the quark-quark weak interaction. The
PVTV interaction is sensitive to more exotic interactions at the fundamental
level, in particular to strong CP violation in the Standard Model Lagrangian,
or even to exotic phenomena predicted in various beyond-the-Standard-Model
scenarios. The presence of these interactions can be revealed either by
studying various asymmetries in polarized scattering of nuclear systems, or by
measuring the presence of non-vanishing permanent electric dipole moments of
nucleons, nuclei and diamagnetic atoms and molecules. In this contribution, we
review the derivation of the nuclear PVTC and PVTV interactions within various
frameworks. We focus in particular on the application of chiral effective field
theory, which allows for a more strict connection with the fundamental
interactions at the quark level. We investigate PVTC and PVTV effects induced
by these potential on several few-nucleon observables, such as the longitudinal
asymmetry in proton-proton scattering and radiative neutron-proton capture, and
the electric dipole momentsof the deuteron and the trinucleon system.
