King's College London

Research portal

First constraints on small-scale non-Gaussianity from UV galaxy luminosity functions

Research output: Contribution to journalArticlepeer-review

Nashwan Sabti, Julian B. Muñoz, Diego Blas

Original languageEnglish
Article number010
JournalJournal of Cosmology and Astroparticle Physics
Volume2021
Issue number1
DOIs
PublishedJan 2021

Bibliographical note

Funding Information: We thank Sandro Tacchella and Andrei Mesinger for insightful comments on the draft of this work. We are also grateful to Gonzalo Palma for discussions on PNG, and the anonymous referee for providing useful feedback on this paper. We acknowledge the use of the packages emcee [92] and corner [93]. NS is a recipient of a King’s College London NMS Faculty Studentship. JBM is supported by NSF grant AST-1813694 at Harvard and the Clay Fellowship at the Smithsonian Astrophysical Observatory. Funding Information: We thank Sandro Tacchella and Andrei Mesinger for insightful comments on the draft of this work. We are also grateful to Gonzalo Palma for discussions on PNG, and the anonymous referee for providing useful feedback on this paper. We acknowledge the use of the packages emcee [92] and corner [93]. NS is a recipient of a King?s College London NMS Faculty Studentship. JBM is supported by NSF grant AST-1813694 at Harvard and the Clay Fellowship at the Smithsonian Astrophysical Observatory. Publisher Copyright: © 2021 IOP Publishing Ltd and Sissa Medialab Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

King's Authors

Abstract

UV luminosity functions provide a wealth of information on the physics of galaxy formation in the early Universe. Given that this probe indirectly tracks the evolution of the mass function of dark matter halos, it has the potential to constrain alternative theories of structure formation. One of such scenarios is the existence of primordial non-Gaussianity at scales beyond those probed by observations of the Cosmic Microwave Background. Through its impact on the halo mass function, such small-scale non-Gaussianity would alter the abundance of galaxies at high redshifts. In this work we present an application of UV luminosity functions as measured by the Hubble Space Telescope to constrain the non-Gaussianity parameter fNL for wavenumbers above a cut-off scale kcut. After marginalizing over the unknown astrophysical parameters and accounting for potential systematic errors, we arrive at a 2σ bound of fNL = 71+426237 for a cut-off scale kcut = 0.1 Mpc1 in the bispectrum of the primordial gravitational potential. Moreover, we perform forecasts for the James Webb Space Telescope and the Nancy Grace Roman Space Telescope, finding an expected improvement of a factor 3–4 upon the current bound.

View graph of relations

© 2020 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454