In order to measuring the displacement field of the positions up to second order, I am interested in rerunning the TNG simulations using the ICs file and the 2LPT option available in Gadget4.
Can i do this just giving Gadget4 the ics_file.hdf5 available and activating the 2LPT flag in the config file?
Or do i need the Fourier modes to re-generate the ICs? If so, where could i find the Fourier modes of the simulations?
Thank you!
Manuel..
Dylan Nelson
15 May
2LPT refers to assumptions made during the creation of the ICs, so you would need to make new ICs.
I would suggest that perhaps you don't need the TNG simulations here. If you are interested in 2LPT (vs Zeldovich), you can create both types of ICs in Gadget4, and run them.
Manuel Arnes
16 May
Hi Dylan,
Thank you for the response.
I though the Zel'dovich displacement field could be removed from the ICs file to obtain the initial glass. Is this feasible?
Another question that came to my mind is that if, for creating the simulations with different resolutions (TNG50-3-Dark and TNG50-4-Dark, for instance), you have used the same Fourier modes and evaluate them on the different of particle positions.
Thank you!
Dylan Nelson
16 May
(1) Yes I suppose this is possible, but again I believe that it would be simpler to create new ICs, of these two different types, from scratch, using the respective functionality in Gadget4. I don't see the need to use the actual TNG ICs.
(2) Yes that is correct, i.e. the same structures form in the same locations, at different resolution realizations of the same volume.
Dear All,
In order to measuring the displacement field of the positions up to second order, I am interested in rerunning the TNG simulations using the ICs file and the 2LPT option available in Gadget4.
Can i do this just giving Gadget4 the ics_file.hdf5 available and activating the 2LPT flag in the config file?
Or do i need the Fourier modes to re-generate the ICs? If so, where could i find the Fourier modes of the simulations?
Thank you!
Manuel..
2LPT refers to assumptions made during the creation of the ICs, so you would need to make new ICs.
I would suggest that perhaps you don't need the TNG simulations here. If you are interested in 2LPT (vs Zeldovich), you can create both types of ICs in Gadget4, and run them.
Hi Dylan,
Thank you for the response.
I though the Zel'dovich displacement field could be removed from the ICs file to obtain the initial glass. Is this feasible?
Another question that came to my mind is that if, for creating the simulations with different resolutions (TNG50-3-Dark and TNG50-4-Dark, for instance), you have used the same Fourier modes and evaluate them on the different of particle positions.
Thank you!
(1) Yes I suppose this is possible, but again I believe that it would be simpler to create new ICs, of these two different types, from scratch, using the respective functionality in Gadget4. I don't see the need to use the actual TNG ICs.
(2) Yes that is correct, i.e. the same structures form in the same locations, at different resolution realizations of the same volume.