Fermionic wave functions and Grassmann fields as possible sources of dark energy L. C. T. Brito, S. H. Pereira, L. N. Barboza, J. C. C. Felipe and J. F. Jesus Eur. Phys. J. C, 82 9 (2022) 821 Published online: 16 September 2022 DOI: 10.1140/epjc/s10052-022-10779-y