Code for obtaining static neutron star solutions in regularized 4D Einstein-Gauss-Bonnet gravity1, for tabulated EoS2, using the KEH/CST numerical scheme3. A C++ version of the Savitzky-Golay filter4 is used, along with some modules from the BOOST C++ library5. In addition the C++ code is wrapped using SWIG6, into a python library which can be imported and used in any way, as shown in swig/test.py.
Compile, using the provided makefile.
EGB.exe takes 7 inputs in total. The parameters are specified using the following flags:
- -f eos_name (The EoS file name).
- -c coupling (The EGB coupling constant in km^2).
- -e central_pressure (The central pressure in dyn/cm^2/10^35).
- -t relative_error (The relative error for the iteration scheme).
- -m maximum_iterations (The maximum number of iterations).
- -l relaxation_factor
- -p print_option:
- 0: Prints gravitational mass M and radius R.
- 1: Prints (0) along with the distance, metric, scalar, energy density and pressure profiles.
For example,
./EGB -f ppsly4.cold.rns1.1.txt -c 20.0 -e 10.0 -t 1e-05 -m 100 -l 0.2 -p 0
typical input parameter space:
- central pressure ~ 0.1-30.0 (10^35 dyn/cm^2)
- coupling ~ 0-70 (km^2)
Footnotes
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https://iopscience.iop.org/article/10.1088/1475-7516/2022/02/033 ↩
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https://ui.adsabs.harvard.edu/abs/2021PhRvD.103l3004B/abstract (table IX) ↩
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https://academic.oup.com/mnras/article/237/2/355/976460, https://ui.adsabs.harvard.edu/abs/1992ApJ...398..203C/abstract, https://gitlab.com/niksterg/rns1-1/ ↩