cout<<"sigma_8= "<<sigma8<<" at "<<z<<" tau "<<tau<<" bah "<<ba.h<<"size "<<ba.bg_size<<" index "<<index<<endl;
#endif
free(pvecback);
planck_assert(sigma8!=-99.," sigma8 could not be computed at "+str(z)+" \n 1) check z_pk and z_max_pk parameters for class \n 2) that you have enabled the Pk computation with : do_mPk = true \n ");