On the cosmology of massive vector fields with SO(3) global symmetry

Bento, M. C.; Bertolami, Orfeu; Moniz, Paulo Vargas; Mourão, José M.; M, P

doi:10.1088/0264-9381/10/2/010

Cited by 88 publications

(128 citation statements)

References 16 publications

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“…As an application, the 1 6 RA 2 vector curvaton model was revisited and shown to result in statistical anisotropy of order unity, which would be excessive if the vector field were to provide the dominant contribution to ζ. In such a case, the only way that excessive statistical anisotropy can be avoided without introducing another dominant (and statistically isotropic) source of curvature perturbations (such as scalar fields) is by considering either a triad of identical vector fields each perpendicular to the other two [24] or hundreds of identical vector fields, randomly oriented in space. In such a case anisotropy in the spectrum or in the expansion can be avoided or suppressed, which means that vector fields could also act as inflatons, without generating anisotropic expansion.…”

Section: Introductionmentioning

confidence: 99%

Vector curvaton with varying kinetic function

2010

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A new model realisation of the vector curvaton paradigm is presented and analysed. The model consists of a single massive Abelian vector field, with a Maxwell type kinetic term. By assuming that the kinetic function and the mass of the vector field are appropriately varying during inflation, it is shown that a scale invariant spectrum of superhorizon perturbations can be generated. These perturbations can contribute to the curvature perturbation of the Universe. If the vector field remains light at the end of inflation it is found that it can generate substantial statistical anisotropy in the spectrum and bispectrum of the curvature perturbation. In this case the non-Gaussianity in the curvature perturbation is predominantly anisotropic, which will be a testable prediction in the near future. If, on the other hand, the vector field is heavy at the end of inflation then it is demonstrated that particle production is approximately isotropic and the vector field alone can give rise to the curvature perturbation, without directly involving any fundamental scalar field. The parameter space for both possibilities is shown to be substantial. Finally, toy-models are presented which show that the desired variation of the mass and kinetic function of the vector field can be realistically obtained, without unnatural tunings, in the context of supergravity or superstrings.

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Section: Introductionmentioning

confidence: 99%

Vector curvaton with varying kinetic function

2010

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“…(8) in the conformal time dη = a −1 (t)dt, the solution being given implicitly in terms of an elliptic function of the first kind [16]. Furthermore, we find that ρ χ 0 = C a 4 (t) , where C is an integration constant.…”

mentioning

confidence: 73%

General cosmological features of the Einstein-Yang-Mills-dilaton system in string theories

Bento

Bertolami

1994

Physics Letters B

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We establish the main features of homogeneous and isotropic dilaton, metric and Yang-Mills field configurations in a cosmological framework. Special attention is paid to the energy exchange between the dilaton and the Yang-Mills field and, in particular, a new energy exchange term is identified. Implications for the Polonyi problem in 4-dimensional string models and in dynamical supersymmetry breaking scenarios are discussed.

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“…Many authors have used gauge fields in cosmology -for inflation as well as for late-time behavior [18][19][20][21][22][23][24][25][26][27][28][29]. A common issue is that spin-1 fields have a preferred direction and therefore break isotropy.…”

Section: Background Modelmentioning

confidence: 99%

“…Equations (21) and (22) in [43] define the energy density perturbation δρ, the divergence of the fluid velocity θ and the shear stress σ. Reading these off from the perturbed stress-energy tensor yields…”

Section: Scalarsmentioning

confidence: 99%

Cosmological consequences of classical flavor-space locked gauge field radiation

Bielefeld

Caldwell

2015

Phys. Rev. D

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We propose a classical SU(2) gauge field in a flavor-space locked configuration as a species of radiation in the early universe, and show that it would have a significant imprint on a primordial stochastic gravitational wave spectrum. In the flavor-space locked configuration, the electric and magnetic fields of each flavor are parallel and mutually orthogonal to other flavors, with isotropic and homogeneous stress-energy. Due to the non-Abelian coupling, the gauge field breaks the symmetry between left-and right-circularly polarized gravitational waves. This broken chiral symmetry results in a unique signal: non-zero cross correlation of the cosmic microwave background temperature and polarization, T B and EB, both of which should be zero in the standard, chiral symmetric case. We forecast the ability of current and future CMB experiments to constrain this model. Furthermore, a wide range of behavior is shown to emerge, depending on the gauge field coupling, abundance, and allocation into electric and magnetic field energy density. The fluctuation power of primordial gravitational waves oscillates back and forth into fluctuations of the gauge field. In certain cases, the gravitational wave spectrum is shown to be suppressed or amplified by up to an order of magnitude depending on the initial conditions of the gauge field.

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On the cosmology of massive vector fields with SO(3) global symmetry

Cited by 88 publications

References 16 publications

Vector curvaton with varying kinetic function

Vector curvaton with varying kinetic function

General cosmological features of the Einstein-Yang-Mills-dilaton system in string theories

Cosmological consequences of classical flavor-space locked gauge field radiation

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