A hemispherical power asymmetry from inflation

By A. Erickcek, M. Kamionkowski, S. Carroll. 2008

150 citations recorded by the source corpus.

Measurements of cosmic microwave background temperature fluctuations by the Wilkinson Microwave Anisotropy Probe indicate that the fluctuation amplitude in one half of the sky differs from the amplitude in the other half. We show that such an asymmetry cannot be generated during single-field slow-roll inflation without violating constraints to the homogeneity of the Universe. In contrast, a multifield inflationary theory, the curvaton model, can produce this power asymmetry without violating the homogeneity constraint. The mechanism requires the introduction of a large-amplitude superhorizon perturbation to the curvaton field, possibly a preinflationary remnant or a superhorizon curvaton-web structure. The model makes several predictions, including non-Gaussianity and modifications to the inflationary consistency relation, that will be tested with forthcoming cosmic microwave background experiments.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/1377d3029e8b521b89aa307eefdd6c641d17db13

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Citations in the corpus

POWER ASYMMETRY IN WMAP AND PLANCK TEMPERATURE SKY MAPS AS MEASURED BY A LOCAL VARIANCE ESTIMATOR (2014, unknown): “Accordingly, theorists are now attempting to reconcile these observations with the current cosmological standard model (see, e.g., Erickcek et al. 2008; Dai et al. 2013; Lyth 2013; Liu et al. 2013; Liddle & Cortês 2013; Mazumdar & Wang 2013; Namjoo et al. 2013; Abolhasani et al. 2014; Cai et al.…”
POWER ASYMMETRY IN COSMIC MICROWAVE BACKGROUND FLUCTUATIONS FROM FULL SKY TO SUB-DEGREE SCALES: IS THE UNIVERSE ISOTROPIC? (2008, background): “Recent theoretical developments(Ackerman et al. 2007; Erickcek et al. 2008; Gordon et al. 2005) have proposed new mechanisms for generating the imprint of a preferred direction in the CMB.”
Large-Angle Anomalies in the CMB (2010, methodology): “A commonly used mechanism to explain such anomalies is inflationary models that contain implicit breaking of isotropy [40, 74–80].”
Cosmology and Fundamental Physics with the Euclid Satellite (2012, methodology): “This would disfavor the simple curvaton spatial gradient scenario (Erickcek et al. 2008) proposed to generate this dipole modulation.”
INCREASING EVIDENCE FOR HEMISPHERICAL POWER ASYMMETRY IN THE FIVE-YEAR WMAP DATA (2009, background): “Considerable efforts have gone towards this goal already (e.g., Ackerman et al. 2007; Böhmer & Mota 2008; Carroll et al. 2008a,b; Chang et al. 2008; Erickcek et al. 2008a,b; Gordon et al. 2005; Gümrükçüoglu et al. 2007; Himmetoglu et al. 2008a,b; Kahniashvili et al. 2008; Kanno et al. 2008;…”