Speaker
Description
The cosmological principle demands statistical homogeneity and isotropy at large enough scales. Although this principle is firmly based on observations, the cosmological principle perhaps requires more than what is actually necessary, the latter being just isotropic expansion with no vorticity. This rationale has led to the formulation of what is called extended Friedmann-Lemaitre-Robertson-Walker (eFLRW) cosmologies; these make a class of irrotational cosmologies that dynamically evolve like the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmologies, simultaneously possessing non-vanishing anisotropic spatial curvature and anisotropic stress that balance each other while the shear vanishes. Thorsrud and others thoroughly investigated such scenarios in the case of an action built from free differential p-forms. In this paper, we extend known results by incorporating gauge theories and self interactions in the search for a more realistic description of the universe. We have found that the non-free 3-form case, where the potential is the sum of a constant term and a quadratic term in the 3 form, and where the latter is not charged under any non-Abelian Lie group, is the only non-trivial circumstance where the shear-free cosmology described above is realized.