Dark energy from primordial inflationary quantum fluctuations.

Institute of Mathematics and Physics, Centre for Cosmology, Particle Physics and Phenomenology, Louvain University, 2 Chemin du Cyclotron, 1348 Louvain-la-Neuve, Belgium.
Physical Review Letters (Impact Factor: 7.73). 09/2010; 105(12):121301. DOI: 10.1103/PhysRevLett.105.121301
Source: PubMed

ABSTRACT We show that current cosmic acceleration can be explained by an almost massless scalar field experiencing quantum fluctuations during primordial inflation. Provided its mass does not exceed the Hubble parameter today, this field has been frozen during the cosmological ages to start dominating the Universe only recently. By using supernovae data, completed with baryonic acoustic oscillations from galaxy surveys and cosmic microwave background anisotropies, we infer the energy scale of primordial inflation to be around a few TeV, which implies a negligible tensor-to-scalar ratio of the primordial fluctuations. Moreover, our model suggests that inflation lasted for an extremely long period. Dark energy could therefore be a natural consequence of cosmic inflation close to the electroweak energy scale.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We provide a general formalism to calculate the infrared correlators of multiple interacting scalar fields in the de Sitter space by means of the stochastic approach. These scalar fields are treated as test fields and hence our result is applicable to the models such as the curvaton scenario where the fields that yield initially isocurvature modes do not contribute to the cosmic energy density during inflationary expansion. The stochastic formalism combined with the argument of conformal invariance of the correlators reflecting the de Sitter isometries allows us to fix the form and amplitude of the three-point functions completely and partially for the four-point functions in terms of calculable quantities. It turns out that naive scaling argument employed in the previous literature does not necessarily hold and we derive the necessary and sufficient condition for the correlator to obey the naive scaling. We also find that correlation functions can in principle exhibit more complicated structure than argued in the literature.
    Physical review D: Particles and fields 10/2012; 86(12).
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Quintessence, a scalar field model, has been proposed to account for the acceleration of the Universe at present. We discuss how accurately quintessence models are discriminated by future cosmological surveys, which include experiments of CMB, galaxy clustering, weak lensing, and the type Ia SNe surveys, by making use of the conventional parameterized dark energy models. We can see clear differences between the thawing and the freezing quintessence models at more than $1\sigma$ ($2\sigma$) confidence level as long as the present equation of state for quintessence is away from $-1$ as $w_X \gtrsim -0.95 (-0.90)$. However, it is found to be difficult to probe the effective mass squared for the potential in thawing models, whose signs are different between the quadratic and the cosine-type potentials. This fact may require us to invent a new estimator to distinguish quintessence models beyond the thawing and the freezing ones.
    Journal of Cosmology and Astroparticle Physics 01/2014; 2014(03). · 5.88 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We show that a longitudinal gauge degree of freedom for a vector field is equivalent to a Pais-Uhlenbeck scalar field. With the help of this equivalence, we can determine natural interactions of this field with scalars and fermions. Since the theory has a global U(1) symmetry, we have the usual conserved current of the charged fields, thanks to which the dynamics of the scalar field is not modified by the interactions. We use this fact to consistently quantize the theory even in the presence of interactions. We argue that such a degree of freedom can only be excited by gravitational effects like the inflationary era of the early universe and may play the role of dark energy in the form of an effective cosmological constant whose value is linked to the inflation scale.
    Journal of High Energy Physics 10/2012; 2013(4). · 6.22 Impact Factor

Full-text (2 Sources)

Available from
May 30, 2014