Fermionic wave functions and Grassmann fields as possible sources of dark energy

• Published in: The European physical journal. C, Particles and fields Vol. 82; no. 9; pp. 1 - 11
• Main Authors: Brito, L. C. T., Pereira, S. H., Barboza, L. N., Felipe, J. C. C., Jesus, J. F.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-09-2022; Springer; Springer Nature B.V; SpringerOpen
• Subjects: Analysis; Astronomical models; Astronomy; Astrophysics and Cosmology; Big Bang theory; Cosmology; Dark energy; Elementary Particles; Equations of state; Hadrons; Heavy Ions; Measurement Science and Instrumentation; Nuclear Energy; Nuclear Physics; Parameters; Perturbation; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Radiation, Background; Regular Article - Theoretical Physics; Specific gravity; String Theory; Supernovae; Wave functions
• ISSN: 1434-6052; 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-022-10779-y

We study a cosmological model with a fermionic field which can be interpreted as a source of dark energy in the universe. Two different approaches were considered, the first one with a massless fermionic field represented by a standard wave-function and the second one where a massive field is a Grassmann variable. The first case naturally reduces to a XCDM model with a constant equation of state parameter, while the last case reproduces a
w
(
z
)CDM model for a massive field, and in the massless limit, the intrinsic Grassmannian property of the field leads always to a vacuum equation of state parameter, irrespective the specific form of the potential. Both cases leads to a dark energy contribution of the fermionic sector. The models are totally compatible with recent cosmological data from Supernovae, BAO and Hubble parameter measurements. A brief study of linear evolution of density perturbations shows that some of the small scale problems related to standard model can be at least alleviated.