<#541#>Figure captions:<#541#>

Fig. 1 Diagrams appearing in the perturbative approach to the renormalization of the axial charge.

a) b) involving positive energy intermediate nucleon states: c) d) involving negative energy intermediate states.

Fig. 2 Axial charge form factor for the #math88#0⁺→0^- transition in ¹⁶O from the orbitals #math89#1p_1/2→2s_1/2 and #math90#1p_3/2→1d_3/2 with relativistic and equivalent non relativistic wave functions.

Fig. 3 Ratio of the relativistic to non relativistic matrix elements of fig. 2 as a function of the momentum transfer.

Fig. 4 Same as fig. 3 for ⁴⁰Ca and the transition #math91#0⁺→0^- from the orbitals #math92#1d_3/2→2p_3/2.

Fig. 5 Ratio of relativistic to non relativistic matrix elements for the transition in fig. 4.