Inflation From Symmetry Breaking Below the Planck Scale
نویسنده
چکیده
We investigate general scalar field potentials V (φ) for inflationary cosmology arising from spontaneous symmetry breaking. We find that potentials which are dominated by terms of order φm with m > 2 can satisfy observational constraints at an arbitrary symmetry breaking scale. Of particular interest, the spectral index of density fluctuations is shown to be independent of the specific form of the potential, depending only on the order m of the lowest non-vanishing derivative of V (φ) near its maximum. The results of a model with a broken SO(3) symmetry illustrate these features. 98.80.Cq, 11.30.Qc Typeset using REVTEX [email protected] [email protected] 1 Scalar field potentials arising from spontaneous symmetry breaking can in general be characterized by the presence of a “false” vacuum, an unstable or metastable equilibrium with nonzero vacuum energy density, and a physical vacuum, for which the vacuum expectation value of the scalar field φ is nonzero. At the physical vacuum, the potential has a stable minimum where the vacuum energy density is defined to vanish. Take a potential V (φ) described by a symmetry breaking scale v and a vacuum energy density Λ: V (φ) = Λf (
منابع مشابه
Natural braneworld inflation and baryogenesis
In natural inflation models, the inflaton is a pseudo Nambu-Goldstone boson and the flatness of the potential is protected by shift symmetries. In this framework, a successful inflation requires the global symmetry to be spontaneously broken at a scale close to the Planck mass. Such a high value of the spontaneous breaking scale may not be legitimate in an effective field theory. On the other h...
متن کاملCosmic microwave background and large-scale structure constraints on a simple quintessential inflation model
We derive constraints on a simple quintessential inflation model, based on a spontaneously broken Φ theory, imposed by the Wilkinson Microwave Anisotropy Probe three-year data (WMAP3) and by galaxy clustering results from the Sloan Digital Sky Survey (SDSS). We find that the scale of symmetry breaking must be larger than about 3 Planck masses in order for inflation to generate acceptable values...
متن کاملA natural solution of μ from the hidden sector
The μ parameter is calculated in supergravity models possessing the U(1)A× U(1)R symmetry. In one natural model without a free mass parameter below the Planck scale, the symmetry breaking scale is identified as the hidden sector squark condensation scale. [email protected] 1
متن کاملUnified Model for Inflation and the Dark Side of the Universe
We present a model with a complex and a real scalar fields and a potential whose symmetry is explicitly broken by Planck-scale physics. For exponentially small breaking, the model accounts for the period of inflation in the early universe and for the period of acceleration of the late universe or for the dark matter, depending on the smallness of the explicit breaking.
متن کاملNatural chaotic inflation in supergravity
We propose a chaotic inflation model in supergravity. In the model the Kahler potential has a Nambu-Goldstone-type shift symmetry of the inflaton chiral multiplet which ensures the flatness of the inflaton potential beyond the Planck scale. We show that chaotic inflation naturally takes place by introducing a small breaking term of the shift symmetry in the superpotential. This may open a new b...
متن کامل