Einstein's legacy in galaxy surveys

Abstract

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. In order to reduce the errors on fNL, we need to include measurements on the largest possible scales. Failure to include the relativistic effects on these scales can introduce significant bias in the best-fit value of fNL from future galaxy surveys.

5 pages, 1 figure. Version published on MNRAS Letters

References in corpus (7)

• The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects
• Measuring primordial non-gaussianity without cosmic variance
• New Perspective on Galaxy Clustering as a Cosmological Probe: General Relativistic Effects
• Cosmological Systematics Beyond Nuisance Parameters : Form Filling Functions
• Relativistic corrections and non-Gaussianity in radio continuum surveys
• General relativistic corrections and non-Gaussianity in large scale structure
• Neglecting Primordial non-Gaussianity Threatens Future Cosmological Experiment Accuracy

Cited by in corpus (4)

• A general relativistic signature in the galaxy bispectrum: the local effects of observing on the lightcone
• Beware of commonly used approximations II: estimating systematic biases in the best-fit parameters
• Disantangling the effects of Doppler velocity and primordial non-Gaussianity in galaxy power spectra
• Probing the primordial Universe with MeerKAT and DES