Beyond the classical distance-redshift test: cross-correlating redshift-free standard candles and sirens with redshift surveys

Suvodip Mukherjee (1, 2) , Benjamin D. Wandelt (1, 2)

1 IAP - Institut d'Astrophysique de Paris
2 Institut Lagrange de Paris

LSST will supply up to $10^6$ supernovae (SNe) to constrain dark energy through the distance-redshift ($D_L$-$z$) test. Obtaining spectroscopic SN redshifts (spec-$z$s) is unfeasible; alternatives are suboptimal and may be biased. We propose a powerful multi-tracer generalization of the Alcock-Paczynski test that pairs redshift-free distance tracers and an overlapping galaxy redshift survey. Cross-correlating $5\times 10^4$ redshift-free SNe with DESI or Euclid outperforms the classical $D_L$-$z$ test with spec-$z$s for all SN. Our method also applies to gravitational wave sirens or any redshift-free distance tracer.

Domaines: Astrophysique [astro-ph]; Instrumentations et Détecteurs [physics.ins-det]

Suvodip Mukherjee, Benjamin D. Wandelt. Beyond the classical distance-redshift test: cross-correlating redshift-free standard candles and sirens with redshift surveys. 2018. ⟨hal-01871901⟩