Construction and classification of differential symmetry breaking operators for principal series representations of the pair $(SO_0(4,1), SO_0(3,1))$ for special parameters

We construct and give a complete classification of all the differential symmetry breaking operators Dλ, νN,m: C^∞(S³, V_λ2N+1) → C^∞(S², Lm, ν), between the spaces of smooth sections of a vector bundle of rank $2N+1$ over the $3$-sphere V_λ2N+1 → S³, and a line bundle over the $2$-sphere Lm, ν → S² in the special case $|m| = N$.