Neutrino-Assisted Early Dark Energy: Theory and Cosmology


Liang, Q. (2022). Neutrino-Assisted Early Dark Energy: Theory and Cosmology. Perimeter Institute. https://pirsa.org/22120055


Liang, Qiuyue. Neutrino-Assisted Early Dark Energy: Theory and Cosmology. Perimeter Institute, Dec. 13, 2022, https://pirsa.org/22120055


          @misc{ pirsa_PIRSA:22120055,
            doi = {10.48660/22120055},
            url = {https://pirsa.org/22120055},
            author = {Liang, Qiuyue},
            keywords = {Cosmology},
            language = {en},
            title = {Neutrino-Assisted Early Dark Energy: Theory and Cosmology},
            publisher = {Perimeter Institute},
            year = {2022},
            month = {dec},
            note = {PIRSA:22120055 see, \url{https://pirsa.org}}

Qiuyue Liang University of Pennsylvania


The tension between measurements of the Hubble constant obtained at different redshifts may provide a hint of new physics active in the relatively early universe, around the epoch of matter- radiation equality. A leading paradigm to resolve the tension is a period of early dark energy, in which a scalar field contributes a subdominant part of the energy budget of the universe at this time. This scenario faces significant fine-tuning problems which can be ameliorated by a non- trivial coupling of the scalar to the standard model neutrinos. These become non-relativistic close to the time of matter-radiation equality, resulting in an energy injection into the scalar that kick- starts the early dark energy phase, explaining its coincidence with this seemingly unrelated epoch. We present a minimal version of this neutrino-assisted early dark energy model, and perform a detailed analysis of its predictions and theoretical constraints. We consider both particle physics constraints — that the model constitute a well-behaved effective field theory for which the quantum corrections are under control, so that the relevant predictions are within its regime of validity — and the constraints provided by requiring a consistent cosmological evolution from early through to late times. Our work paves the way for testing this scenario using cosmological data sets. 

Zoom link:  https://pitp.zoom.us/j/95613703701?pwd=amlmNUdXdXFuQitFVk8xTnNwcDlMUT09