| Автор | Christopher M. Hirata |
| Дата выпуска | 2009-09-01 |
| dc.description | Recent analyses of the cosmic microwave background (CMB) maps from the WMAP satellite have uncovered evidence for a hemispherical power anomaly, i.e. a dipole modulation of the CMB power spectrum at large angular scales with an amplitude of ±14 percent. Erickcek et al have put forward an inflationary model to explain this anomaly. Their scenario is a variation on the curvaton scenario in which the curvaton possesses a large-scale spatial gradient that modulates the amplitude of CMB fluctuations. We show that this scenario would also lead to a spatial gradient in the amplitude of perturbations σ<sub>8</sub>, and hence to a dipole asymmetry in any highly biased tracer of the underlying density field. Using the high-redshift quasars from the Sloan Digital Sky Survey, we find an upper limit on such a gradient of |∇σ<sub>8</sub>|/σ<sub>8</sub> < 0.027r<sub>lss</sub><sup>−1</sup> (99% posterior probability), where r<sub>lss</sub> is the comoving distance to the last-scattering surface. This rules out the simplest version of the curvaton spatial gradient scenario. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Constraints on cosmic hemispherical power anomalies from quasars |
| Тип | paper |
| DOI | 10.1088/1475-7516/2009/09/011 |
| Electronic ISSN | 1475-7516 |
| Журнал | Journal of Cosmology and Astroparticle Physics |
| Том | 2009 |
| Первая страница | 11 |
| Последняя страница | 011 |
| Аффилиация | Christopher M. Hirata; Caltech, M/C 350-17, Pasadena, CA 91125, U.S.A. |
| Выпуск | 09 |
