Extreme Equations of State in Binary Neutron Star Mergers


Hunter Bass


John Stroud (INT Graduate Student), email:


Some basic coding experience would be beneficial but is not required.

What Students Will Do:

Students will gain a background on the basic tools for studying cold non-rotating compact objects. The student will also gain knowledge in current models of exotic phenomena at supranuclear densities. The student will gain experience in the numerical techniques for solving problems in computational physics, and the student will gain experience utilizing a high performance computing architecture to run simulations.

Expected Length:

One year

Figure for INTURN 24-6

Image Credit: NASA/Goddard Space Flight Center

Project Description:

Neutron Stars are among the most compact objects in the universe, as such they offer one of  the only opportunities to study properties of matter at densities unachievable in any terrestrial setting. This allows one to gain insights to the Equation of State (EOS) which describes many of the properties of dense matter. At such high densities exotic phenomena such as presence of deconfined quark matter in neutron stars [1]. In addition dark matter may be present in the cores of neutron stars [2].  Gravitational wave astronomy may offer a method to test the validity of these models, and with new and improved detectors coming in the next few decades there will be a wealth of binary compact object mergers available [3]. However, observations are heavily guided through simulations of merger events which have only been made possible recently through high performance computing.  In this project the student will assist in coming up with simple models of extreme equations of state containing the effects of exotic phenomena  such as free quark matter or dark matter.  These models will be used in binary neutron star merger simulations run on the UW’s Hyak supercomputer.


[1] Larry Mclerran, Sanjay Reddy, Quarkyonic Matter and Neutron Stars (2018) 

[2] Ben Kain, Dark Matter Admixed Neutron Stars (2021) 

[3] M. Bailes et. al, Gravitational Wave Astronomy in the 2020s and 2030s (2021)