Cosmology of Cubic Poincar’e Gauge gravity
Sebastian Bahamonde, Rebecca Briffa, Konstantinos Dialektopoulos, Damianos Iosifidis, Jackson Levi Said
arXiv:2506.17017v2 Announce Type: replace-cross
Abstract: In this paper, we study flat FLRW cosmology for a Poincar’e gauge theory containing cubic invariants that is free from ghosts in arbitrary backgrounds in the axial and vector sectors of the torsion tensor. The new degrees of freedom can be related to hypermomentum but continue to be dynamical even in vacuum. These extra degrees of freedom open a more natural way in which to construct potential gravitational models that provide possible ways to modify astrophysical and cosmological physics. In this framework, we study two particular branches of the theory where preliminary routes of exploring these new variables are exposed. The first is the branch where the hypermomentum vanishes, while the second branch involves the setting where the perfect fluid and hypermomentum parts of the sources are independently conserved. In both settings, we find generically faster expanding cosmologies with similar estimates of the cosmic matter content as in the standard model of cosmology. Cubic Poincar’e Gauge gravity offers an interesting theoretical basis on which to study cosmology, and indicates some preliminary positive constraints when compared with observational constraints.arXiv:2506.17017v2 Announce Type: replace-cross
Abstract: In this paper, we study flat FLRW cosmology for a Poincar’e gauge theory containing cubic invariants that is free from ghosts in arbitrary backgrounds in the axial and vector sectors of the torsion tensor. The new degrees of freedom can be related to hypermomentum but continue to be dynamical even in vacuum. These extra degrees of freedom open a more natural way in which to construct potential gravitational models that provide possible ways to modify astrophysical and cosmological physics. In this framework, we study two particular branches of the theory where preliminary routes of exploring these new variables are exposed. The first is the branch where the hypermomentum vanishes, while the second branch involves the setting where the perfect fluid and hypermomentum parts of the sources are independently conserved. In both settings, we find generically faster expanding cosmologies with similar estimates of the cosmic matter content as in the standard model of cosmology. Cubic Poincar’e Gauge gravity offers an interesting theoretical basis on which to study cosmology, and indicates some preliminary positive constraints when compared with observational constraints.