Initial Conditions difference between snap_ics.hdf5 and Gadget4 output at z=127 using the same seed
Manuel Arnes
24 Nov
Hi,
I am trying to generate the same IC as TNG50-3 using Gadget4, which has N-GenIC implemented in. The seed I am using is 8458657 and the initial redshift is 127.
However, I see that the particle positions and velocities are not the same between the two ICs. Is this expected? Since I have read in the forum that in TNG a modified version of N-GenIC is used.
There will be differences - the TNG ICs were made, for example, using a tabulated transfer function made with CAMB. When you are running G4, you are taking a different choice here. There may be others. Nonetheless, I expect similar large-scale structure will exist (i.e. at z=0), have you checked?
Hi,
I am trying to generate the same IC as TNG50-3 using Gadget4, which has N-GenIC implemented in. The seed I am using is 8458657 and the initial redshift is 127.
However, I see that the particle positions and velocities are not the same between the two ICs. Is this expected? Since I have read in the forum that in TNG a modified version of N-GenIC is used.
Thank you in advance!
Manuel Arnés
There will be differences - the TNG ICs were made, for example, using a tabulated transfer function made with CAMB. When you are running G4, you are taking a different choice here. There may be others. Nonetheless, I expect similar large-scale structure will exist (i.e. at z=0), have you checked?