2018/01/31 by Azadeh Moradinezhad Dizgah, Hayden Lee, Julian B. Muñoz +2 · 3 citations
Physics and Astronomy · #Amplitude #Anisotropy #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Bispectrum #Cosmic microwave background #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Galaxy #Inflation (cosmology) #Non-Gaussianity #Physics #Quantum mechanics #Redshift #Spectral density #Spins #Statistics #Universe #astro-ph.CO #hep-ph
paper · pdf · doi:10.1088/1475-7516/2018/05/013
New subsections on the impact of theoretical error and non-Gaussian corrections to the variance added. v2 matches the published version
openalex publication_date 2018/05/03 · arxiv created 2018/05/11 · arxiv updated 2018/05/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Massive spinning particles, if present during inflation, lead to a distinctive bispectrum of primordial perturbations, the shape and amplitude of which depend on the masses and spins of the extra particles. This signal, in turn, leaves an imprint in the statistical distribution of galaxies; in particular, as a non-vanishing galaxy bispectrum, which can be used to probe the masses and spins of these particles. In this paper, we present for the first time a new theoretical template for the bispectrum generated by massive spinning particles, valid for a general triangle configuration. We then proceed to perform a Fisher-matrix forecast to assess the potential of two next-generation spectroscopic galaxy surveys, EUCLID and DESI, to constrain the primordial non-Gaussianity sourced by these extra particles. We model the galaxy bispectrum using tree-level perturbation theory, accounting for redshift-space distortions and the Alcock-Paczynski effect, and forecast constraints on the primordial non-Gaussianity parameters marginalizing over all relevant biases and cosmological parameters. Our results suggest that these surveys would potentially be sensitive to any primordial non-Gaussianity with an amplitude larger than f NL ≈ 1, for massive particles with spins 2, 3, and 4. Interestingly, if non-Gaussianities are present at that level, these surveys will be able to infer the masses of these spinning particles to within tens of percent. If detected, this would provide a very clear window into the particle content of our Universe during inflation.