Vector field models of inflation and dark energy

By Tomi Koivisto, D. Mota. 2008

270 citations recorded by the source corpus.

We consider several new classes of viable vector field alternatives to the inflaton and quintessence scalar fields. Spatial vector fields are shown to be compatible with the cosmological anisotropy bounds if only slightly displaced from the potential minimum while dominant, or if driving an anisotropic expansion with nearly vanishing quadrupole today. The Bianchi I model with a spatial field and an isotropic fluid is studied as a dynamical system, and scaling solutions of several types are found. On the other hand, time-like fields are automatically compatible with large-scale isotropy. We show that they can be dynamically important if non-minimal gravity couplings are taken into account. We reconstruct as an example a vector–Gauss–Bonnet model which generates the concordance model acceleration at late times and supports an inflationary epoch at high curvatures. The evolution of the vortical perturbations in such models is computed.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/9754485258b7dd75a38ed2fb528b652824fd1a58

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Citations in the corpus

A systematic approach to generalisations of General Relativity and their cosmological implications (2018, background): “In all these considerations in order to guarantee an isotropic expansion, one has to either assume a large number of randomly oriented vector fields, or a triplet of orthogonal vector fields [240] or a vector field with only the zero component non-vanishing [241] (massive vector field).”
Vector inflation (2008, background): “The lightest vector fields might also force the late time acceleration of the Universe.”
Cosmology and Fundamental Physics with the Euclid Satellite (2012, unknown): “Approaches to deal with the anisotropy have been based on a “triad” of three identical vectors aligned with the three axis [77], a large number of randomly oriented fields averaging to isotropy [536], time-like [693] or sub-dominant [425] fields.”
Anisotropic dark energy: dynamics of the background and perturbations (2008, background): “Vector fields will be considered in much more detail in elsewhere [22]; we have found that such models can also feature constant equations of state δ and γ in special cases, though they in general are dynamical, depending on the potentials and couplings [22].”
Dynamical systems applied to cosmology: Dark energy and modified gravity (2017, methodology): “Koivisto (2008) used dynamical systems techniques to analyse power-law and exponential forms of the nonlocal term in FLRW cosmology.”