New ultralight scalar particles and the mass-radius relation of white dwarfs -- the important role of Sirius B

Kai Bartnick, Detlev Koester, Rolf-Peter Kudritzki +3

We present the equation of state for two classes of new ultralight particles, a scalar field coupling to electrons and a light ${\mathbb{Z}}_{\mathcal{N}}$ QCD axion field coupling to…