Einstein's legacy in galaxy surveys

Understand

Non-Gaussianity in the primordial fluctuations that seeded structure formation produces a signal in the galaxy power spectrum on very large scales.

• This signal contains vital information about the primordial Universe, but it is very challenging to extract, because of cosmic variance and large-scale systematics - especially after the Planck experiment has already ruled out a large amplitude for the signal.
• Cosmic variance and experimental systematics can be alleviated by the multi-tracer method.
• Here we address another systematic - introduced by not using the correct relativistic analysis of the power spectrum on very large scales.