Bulk viscosity from neutron decays in dense matter

Oral-In-person

Abstract

When the dense matter inside neutron stars is compressed, it is pushed out of chemical equilibrium. To reestablish equilibrium, neutron decays and their inverses occur, resulting in bulk-viscous energy dissipation. In standard npe matter, the bulk viscosity due to the Urca process leads to bulk viscosity with one resonant peak as a function of temperature. I will discuss how the value of bulk viscosity at the peak is related to the symmetry energy as well as the possibility of a second peak in the bulk viscosity at higher temperature due to neutron decay into dark baryons.

Publication: https://arxiv.org/abs/2509.25838
https://arxiv.org/abs/2505.12133

Presenters

  • Steven Harris

    • Iowa State University

Authors

  • Steven Harris

    • Iowa State University
  • Charles Horowitz

    • Indiana University Bloomington