Rights statement: © 2014 American Physical Society
Final published version, 114 KB, PDF document
Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Article number | 127303 |
---|---|
<mark>Journal publication date</mark> | 26/06/2014 |
<mark>Journal</mark> | Physical Review D |
Issue number | 12 |
Volume | 89 |
Number of pages | 5 |
Publication Status | Published |
<mark>Original language</mark> | English |
The hemispherical power asymmetry observed by Planck and WMAP can be interpreted as due to a spatially-varying and scale-dependent component of the adiabatic power spectrum. We derive general constraints on the magnitude and scale-dependence of a component with a dipole spatial variation. The spectral index and the running of the spectral index can be significantly shifted from their inflation model values, resulting in a smaller spectral index and a more positive running. A key prediction is a hemispherical asymmetry of the spectral index and of its running. Measurement of these asymmetries can test the structure of the perturbation responsible for the cosmic microwave background power asymmetry.