Investigation of compact stars with heavy baryons and quarks: second period

• Applicant: Privatdozent Dr. Armen Sedrakian
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields ; Astrophysics and Astronomy
• Term: from 2020 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 433859871

• Final Report Year: 2025

Final Report Abstract

This project continued into the second stage the exploration of compact stars with a focus on their properties related to the behavior of high-density matter that contains heavy baryons (hyperons and ∆-resonances) and quarks. The key idea was to extend the existing codes for heavy-baryon and quark matters and computation of key thermodynamic quantities of such matter, including equation of state and composition at non-zero temperature. These results were compared to the macroscopic properties of compact stars, such as mass, radius, moment of inertia, and deformability to place constraints on the underlying models. We have also continued the studies of transport properties of dense matter, in particular, the bulk viscosity of nucleonic matter. The focus has been on the muon component in the matter in neutrino transparent and trapped regimes. As a first application of the obtained finitetemperature equations of state of hyperonic matter, we have computed static and rapidly rotating hot compact star configurations. Our nucleonic and hyperonic equations of state were exported to the CompOSE repository for the use of the numerical relativity community.

Link to the final report

https://doi.org/10.34657/23838

Publications

• Bulk Viscosity of Relativistic npeμ Matter in Neutron-Star Mergers. Particles, 5(3), 361-376.
  Alford, Mark; Harutyunyan, Arus & Sedrakian, Armen
  
• Delta-resonances and hyperons in proto-neutron stars and merger remnants. The European Physical Journal A, 58(7).
  Sedrakian, Armen & Harutyunyan, Arus
  
• Massive relativistic compact stars from SU(3) symmetric quark models. Physics Letters B, 834, 137470.
  Fu, Han Rui; Li, Jia Jie; Sedrakian, Armen & Weber, Fridolin
  
• Baryonic models of ultra-low-mass compact stars for the central compact object in HESS J1731-347. Physics Letters B, 844, 138062.
  Li, Jia Jie & Sedrakian, Armen
  
• Bulk viscosity from Urca processes: npeμ matter in the neutrino-transparent regime. Physical Review D, 108(8).
  Alford, Mark; Harutyunyan, Arus & Sedrakian, Armen
  
• Differential rotation in compact objects with hyperons and delta isobars. Astronomische Nachrichten, 345(2-3).
  Farrell, Delaney; Weber, Fridolin; Li, Jia Jie & Sedrakian, Armen
  
• Heavy baryons in compact stars. Progress in Particle and Nuclear Physics, 131, 104041.
  Sedrakian, Armen; Li, Jia Jie & Weber, Fridolin
  
• Impact of Multiple Phase Transitions in Dense QCD on Compact Stars. Particles, 6(3), 713-730.
  Sedrakian, Armen
  
• New Covariant Density Functionals of Nuclear Matter for Compact Star Simulations. The Astrophysical Journal, 957(1), 41.
  Li, Jia-Jie & Sedrakian, Armen
  
• Phenomenological Relativistic Second-Order Hydrodynamics for Multiflavor Fluids. Symmetry, 15(2), 494.
  Harutyunyan, Arus & Sedrakian, Armen
  
• Two first-order phase transitions in hybrid compact stars: Higher-order multiplet stars, reaction modes, and intermediate conversion speeds. Physical Review D, 107(10).
  Rau, Peter B. & Sedrakian, Armen
  
• Ultracompact hybrid stars consistent with multimessenger astrophysics. Physical Review D, 107(2).
  Li, Jia Jie; Sedrakian, Armen & Alford, Mark
  
• Universal relations for compact stars with heavy baryons. Physical Review C, 108(2).
  Li, Jia Jie; Sedrakian, Armen & Weber, Fridolin
  
• Electrical conductivity of a warm neutron star crust in magnetic fields: Neutron-drip regime. Physical Review C, 109(5).
  Harutyunyan, Arus; Sedrakian, Armen; Gevorgyan, Narine T. & Hayrapetyan, Mekhak V.
  
• Finite-temperature equations of state of compact stars with hyperons: three-dimensional tables. The European Physical Journal A, 60(6).
  Tsiopelas, Stefanos; Sedrakian, Armen & Oertel, Micaela
  
• Hybrid Star Models in the Light of New Multimessenger Data. The Astrophysical Journal, 967(2), 116.
  Li, Jia Jie; Sedrakian, Armen & Alford, Mark