We point out that a light scalar field fluctuating around a symmetry-enhanced point can generate large non-Gaussianity in density fluctuations. We name such a particle an 'ungaussiton', a scalar field dominantly produced by the quantum fluctuations, generating sizable non-Gaussianity in the density fluctuations. We derive a consistency relation between the bispectrum and the trispectrum, τNL∼10 3fNL4/3, which can be extended to arbitrarily high order correlation functions. If such a relation is confirmed by future observations, it will strongly support this mechanism.
- Cosmological perturbation theory
- Physics of the early universe
ASJC Scopus subject areas
- Astronomy and Astrophysics