Axial gravity, massless fermions and trace anomalies L. Bonora, M. Cvitan, P. Dominis Prester, A. Duarte Pereira, S. Giaccari and T. Štemberga Eur. Phys. J. C, 77 8 (2017) 511 Published online: 01 August 2017 DOI: 10.1140/epjc/s10052-017-5071-7