Antisymmetric galaxy cross-correlations as a cosmological probe

Abstract

The auto-correlation 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 $\mathbf{r}$, is not necessarily the same as that for a pair separated by $-\mathbf{r}$. 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 CMB cold spot. New ways to seek cosmic parity breaking are also possible.

6 pages, 1 figure; version matching publication in PRD

References in corpus (9)

• The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects
• A Hemispherical Power Asymmetry from Inflation
• Local Voids as the Origin of Large-angle Cosmic Microwave Background Anomalies I
• A Scale-Dependent Power Asymmetry from Isocurvature Perturbations
• Broken Isotropy from a Linear Modulation of the Primordial Perturbations
• Three-Point Correlation Functions of SDSS Galaxies: Luminosity and Color Dependence in Redshift and Projected Space
• Cosmological perturbations from vector inflation
• Cosmological evolution in vector-tensor theories of gravity
• A group-galaxy cross-correlation function analysis in zCOSMOS

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