This test follows the computation performed in Camelio et al., 2019. While the code is not perfectly identical to the one used for the paper, the code changes have been minimal.

For a careful theoretical understanding, one has to investigate the exact model parameters that are employed. The equation of state follows the form (Eq. 45 of Camelio et al., 2019):

with the thermal barotropic law (Eq. 45 of Camelio et al., 2019)

and the rotational barotropic law (Eq. 24 of Camelio et al., 2019)

with (Eq. 38 of Camelio et al., 2019)

After following the outlined installation guide, you can run a first test configuration

./kepler.x

This will prompt an output in which you see the computation of a sequence of TOV stars, e.g.,

TOV: cycle=           1 surf=        1011 M=   1.9273597635660831      x=   1.0000000000000000      dx=   1.0000000000000000
TOV: cycle=           2 surf=         504 M=   1.9290154365593117      x=   2.0000000000000000      dx= -0.11245266184992331
TOV: cycle=           3 surf=         535 M=   1.9293689630752393      x=   1.8875473381500767      dx= -0.15463603290380235
TOV: cycle=           4 surf=         583 M=   1.9290878086382708      x=   1.7329113052462743      dx=   2.8155619686886402E-002
...

followed by the computation of the rotating configuration

 >    1: max|hden - old hden| = 0.8462E-04
 >    2: max|hden - old hden| = 0.1179E-04
 >    3: max|hden - old hden| = 0.1272E-04
 >    4: max|hden - old hden| = 0.1680E-04
 ...

Once in a while, when the required tolerance is met, you see the final output:

## find_kep: iteration=            1
 gravitivational mass =    1.9406076078197565     
 rest mass            =    2.2703990441460347     
 total entropy        =    0.0000000000000000     
 angular momentum     =   0.53421095941810259     
 equatorial radius    =    5.7849999999999211       =    8.5422992991762108       km
 radii ratio          =   0.98271391529818508     
 equatorial Omega     =    1.0000000000000000E-002
 keplerian Omega      =    6.2028428506061051E-002
 disk mass            =    0.0000000000000000     
 central rho          =    1.7355999999999999E-003
 axial Omega          =    1.0000000000000000E-002
 error flag           =            0

This was simply the first step of the iteration and you see that the code is continuously increasing the mass and tries to find the maximum mass that you can reach at the Kepler limit. For this dummy example, you should arrive at:

This computation can take a while (if you don't change the input parameters), so be patient.