  We study the magnon-mediated pairing between fermions on the surface of a
topological insulator (TI) coupled to a ferromagnetic insulator with a tilted
mean field magnetization. Tilting the magnetization towards the interfacial
plane reduces the magnetic band gap and leads to a shift in the effective TI
dispersions. We derive and solve the self-consistency equation for the
superconducting gap in two different situations, where we neglect or include
the frequency dependence of the magnon propagator. Neglecting the frequency
dependence results in p-wave Amperean solutions. We also find that tilting the
magnetization into the interface plane favors Cooper pairs with center of mass
momenta parallel to the magnetization vector, increasing $T_c$ compared to the
out-of-plane case. Including the frequency dependence of the magnon propagator,
and solving for a low number of Matsubara frequencies, we find that the
eigenvectors of the Amperean solutions at the critical temperature are
dominantly odd in frequency and even in momentum, thus opening the possibility
for odd-frequency Amperean pairing.
