Details

Autor(en) / Beteiligte

• Dai, Liang
• Kamionkowski, Marc
• Kovetz, Ely D.
• Raccanelli, Alvise
• Shiraishi, Maresuke

Titel

Antisymmetric galaxy cross-correlations as a cosmological probe

Ist Teil von

• Physical review. D, 2016-01, Vol.93 (2), Article 023507

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The autocorrelation between two members of a galaxy population is symmetric under the interchange of the two galaxies being correlated. The cross-correlation between two different types of galaxies, separated by a vector r, is not necessarily the same as that for a pair separated by -r. Local anisotropies in the two-point cross-correlation function may thus indicate a specific direction which when mapped as a function of position trace out a vector field. This vector field can then be decomposed into longitudinal and transverse components, and those transverse components written as positive- and negative-helicity components. A locally asymmetric cross-correlation of the longitudinal type arises naturally in halo clustering, even with Gaussian initial conditions, and could be enhanced with local-type non-Gaussianity. Early-Universe scenarios that introduce a vector field may also give rise to such effects. These antisymmetric cross-correlations also provide a new possibility to seek a preferred cosmic direction correlated with the hemispherical power asymmetry in the cosmic microwave background and to seek a preferred location associated with the cosmic microwave background cold spot. New ways to seek cosmic parity breaking are also possible.