Year: 2026
Type: preprint
Abstract: In Seesaw Cosmology, a scalar field reheats the Standard Model (SM) through right-handed neutrinos (RHNs), which generate tiny neutrino masses through the seesaw mechanism. When RHNs rapidly fill a restricted momentum-space region, expansion continually opens new fermionic states that are refilled by subsequent scalar decays, maintaining an approximately constant physical RHN density. This gives rise to a novel heating regime in which the SM temperature increases with the scale factor as $T \propto a^{+3/8}$, in sharp contrast to the conventional $T \propto a^{-3/8}$ scaling during matter-dominated reheating.
Source: arXiv (Cornell University)
Authors: Bernal, Nicolás, Fong, Chee Sheng
Institutions: New York University Abu Dhabi, Universidade Federal do ABC
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G103507813, G1105844351, G1175115578, G121313887, G1272900390, G1938719665, G1976036500, G2148579211, G2239994957, G2262748287, G2382844429, G2917513873, G295657101, G300979063, G3480869486, G4212894969, G425668148, G4546701545, G464105488, G4728539003, G491712853, G5080475149, G5209569390, G5635532810, G7084143925, G714608666, G7395345766, G7805626310, G7863371703, G8497050386, G863151887, G8667377315
OpenAlex ID: W7213500460