Burgers equation for the bulk viscous pressure of quark matter

The dissipative properties of relativistic strongly interacting nuclear matter significantly influence the damping of stellar oscillations and density fluctuations during compact star mergers. In this work, we derive the evolution equation for the bulk viscous pressure in unpaired quark matter under...

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Detalles Bibliográficos
Autores: Hernández, José Luis, Manuel, Cristina, Säppi, Saga, Tolos, Laura
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2026
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/419659
Acceso en línea:http://hdl.handle.net/10261/419659
http://arxiv.org/abs/2507.00794v2
Access Level:acceso abierto
Palabra clave:Nuclear matter in neutron stars
Perturbative QCD
Quantum chromodynamics
Quark matter
Neutron stars & pulsars
Relativistic hydrodynamics
Descripción
Sumario:The dissipative properties of relativistic strongly interacting nuclear matter significantly influence the damping of stellar oscillations and density fluctuations during compact star mergers. In this work, we derive the evolution equation for the bulk viscous pressure in unpaired quark matter under small deviations from equilibrium. Our analysis reveals that it behaves like a two-component Burgers fluid. We identify four key transport coefficients -- two relaxation times and two bulk viscosity coefficients -- expressed in terms of equilibrium parameters and electroweak nonleptonic and semi-leptonic decay rates. The transport coefficients are evaluated for two distinct equations of state: one based on perturbative quantum chromodynamics and the other on a modified MIT bag model, valid in different density regimes. We also determine the temperature and density region where nonleptonic electroweak processes dominate the dissipation. Our formulation establishes a new way of describing bulk viscous effects in quark matter, applicable for numerical simulations of compact star mergers.