  We study the competition between disorder and singlet superconductivity in a
quasi-1d system. We investigate the applicability of the Anderson theorem,
namely that time-reversal conserving (non-magnetic) disorder does not impact
the critical temperature, by opposition to time-reversal breaking disorder
(magnetic). To do so we examine a quasi-1d system of spin 1/2 fermions with
attractive interactions and forward scattering disorder using field theory
(bosonization). By computing the superconducting critical temperature ($T_c$),
we find that for non-magnetic disorder the Anderson theorem also holds in the
quasi-1D geometry. On the contrary, magnetic disorder has an impact on the
critical temperature, that we investigate by deriving renormalization group
(RG) equations describing the competition between the disorder and the
interactions. Computing the critical temperature as a function of disorder
strength, we see that different regimes arise depending on the strength of
interactions. We discuss possible platforms where to observe this in cold atoms
and condensed matter.
