[FLASH-BUGS] a problem in the unit of active particles (massive)

[Congyao Zhang]

Hello,

I have a question about  the unit of active particles (massive),

In the user-guide, the equation shown in the part "Cosmological
variable-timestep leapfrog" shows that "A= -2 *  a_dot / a", where a is the
scale factor.

I copy the source code below (from the file pt_advancLeapfrog_cosmos.F90),

  alpha    = 2*Hubble/sOld * sqrt(OmegaM/sOld-OmegaCurv+OmegaL*sOld**2)
  dotalpha = 2*Hubble**2 * (-3*OmegaM + 2*OmegaCurv*sOld)/sOld**3

1. there is a "sign" difference between the equation in the user-guide and
the code.
2. there seems an additional factor of 2 in dotalpha. It should be
"dotalpha = Hubble**2 * (-3*OmegaM + 2*OmegaCurv*sOld)/sOld**3". Am I
correct?

Thank you for your time!

Best regards,
Congyao
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