Speaker
Pedro Schwaller
Description
Searches for neutrino isocurvature usually constrain a specific linear combination of isocurvature perturbations. We will discuss realistic cosmological scenarios and argue that in general both, neutrino and matter isocurvature perturbations are generated, whose ratio we parameterize by a newly introduced mixing angle. We obtain the first limits on this new mixing angle from PLANCK data, and find modest evidence for non-vanishing pure neutrino isocurvature.
We further show that in the presence of non-zero dark radiation isocurvature, the induced dark matter isocurvature can distinguish different production mechanisms such as freeze-in and freeze-out.
Authors
Christopher Gerlach
(Johannes Gutenberg University Mainz)
Pedro Schwaller
Wolfram Ratzinger
(Weizmann Institute)