Cosmology cooling time-step
What is the correct time-step to use in the cooling routine?
Is it dt ? dt/a ? dt/a^2 ? dt/a^x ?
This is mainly for me to remember to do something here.
@rgb @lhausammann @jborrow you might be interested in this debate.
At the moment the time-step passed to the cooling routine is
age_of_universe(a_end_of_step) - age_of_universe(a_begin_of_step)