Open/closed universe

[MarcoMarinucci]

Hello everyone,

I would run Galacticus with a cosmology which is not flat.
Now, what I have always done was to run Gal. with the option , but I now put values for OmegaMatter and OmegaLambda such that OmegaMatter + OmegaLambda > or < 1 I have the following fatal error

Fatal error:
no fitting formula available for this cosmology
Occurred at:
function:bryanNorman1998ConstructorInternal
file:structure_formation.virial_density_contrast.Bryan_Norman.F90 [line 115]

What should I do? I wasn't able to find any other option for cosmologyFunctions in other scripts or in the notes.

Thanks for helping!

Marco

[abensonca]

Hi Marco: The problem here is that Bryan & Norman (1998) only provide fitting functions for the virial density contrast $\Delta_\mathrm{vir}$ for flat universes, or open universe with $\Omega_\Lambda=0$. So, in your case it doesn't have a fitting function that can be applied.

The solution would be to use a different virial density contrast class. The bryanNorman1998 class is just a fitting function to the results of the spherical collapse model. So, you could switch to the virialDensityContrastSphericalCollapseClsnlssMttrCsmlgclCnstnt class:

<virialDensityContrast value="sphericalCollapseClsnlssMttrCsmlgclCnstnt"/>

which implements the full spherical collapse model in cosmologies containing matter plus a cosmological constant, and should work for non-flat cases.

[MarcoMarinucci]

Hi Andrew, thanks.

I already have that option for the virial density contrast:

Structure formation options
linearGrowth value="collisionlessMatter"
criticalOverdensity value="sphericalCollapseClsnlssMttrCsmlgclCnstnt"
virialDensityContrast value="sphericalCollapseClsnlssMttrCsmlgclCnstnt"

but I still have the error.
the cosmology I want to run is

Cosmological parameters and options
cosmologyFunctions value="matterLambda"
cosmologyParameters value="simple"
HubbleConstant value="66.62000"
OmegaMatter value=" 0.3194"
OmegaDarkEnergy value=" 0.7146"
OmegaBaryon value=" 0.0502"
temperatureCMB value=" 2.72548"
cosmologyParameters

I also attach the xml file as a txt. Note that a similar file, but with OmegaMatter + OmegaLambda = 1 and exactly the same other parameters is normally running.

thanks!
Marco

z1_sephigh_rs12.txt

[abensonca]

Ok, I see the problem. The model used by the li2020 class for subhalo initial orbital parameters is based on the Bryan & Norman (1998) definition of virial density contrast. Galacticus internally converts to your preferred virial density contrast. But, in this case it can't do that as no fitting function is available.

Given that Bryan & Norman is a fit to the spherical collapse model I'll add an option to allow the li2020 class to assume that no conversion is necessary. I'll let you know when I have this implemented.

[abensonca]

This should now be fixed in the latest update to Galacticus. For cosmologies where Bryan & Norman (1998) don't provide a fitting function it will automatically revert to using numerical solutions to the spherical top-hat collapse model.