N-bodyシミュレーションを行いたいと思っていて、以下のパラメーターを変化させられるのですが、それぞれの意味がよくわかりません。。どなたかわかる方いたら教えていただきたいです。
ソフト、バージョン、関係するURLは「GADGET-2 version2.0.7 http://wwwmpa.mpa-garching.mpg.de/gadget/」です。
Nmesh 128 % This is the size of the FFT grid used to compute the displacement field. One should have Nmesh >= Nsample.
Nsample 128 % sets the maximum k that the code uses, i.e. this effectively determines the Nyquist frequency that the code assumes, k_Nyquist = 2*PI/Box * Nsample/2 Normally, one chooses Nsample such that Ntot = Nsample^3, where Ntot is the total number of particles
Box 150000.0 % Periodic box size of simulation
FileBase ics % Base-filename of output files
OutputDir ./ICs/ % Directory for output
GlassFile dummy_glass.dat % File with unperturbed glass or Cartesian grid
TileFac 8 % Number of times the glass file is tiled in each dimension (must be an integer)
Omega 0.3 % Total matter density (at z=0)
OmegaLambda 0.7 % Cosmological constant (at z=0)
OmegaBaryon 0.0 % Baryon density (at z=0)
HubbleParam 0.7 % Hubble paramater (may be used for power spec parameterization)
Redshift 63 % Starting redshift
Sigma8 0.9 % power spectrum normalization
SphereMode 1 % if "1" only modes with |k| < k_Nyquist are used (i.e. a sphere in k-space), otherwise modes with |k_x|,|k_y|,|k_z| < k_Nyquist are used (i.e. a cube in k-space)
WhichSpectrum 0 % "1" selects Eisenstein & Hu spectrum,"2" selects a tabulated power spectrum in the file 'FileWithInputSpectrum' otherwise, Efstathiou parametrization is used
FileWithInputSpectrum input_spectrum.txt % filename of tabulated input spectrum (if used)
InputSpectrum_UnitLength_in_cm 3.085678e24 % defines length unit of tabulated input spectrum in cm/h. Note: This can be chosen different from UnitLength_in_cm
ReNormalizeInputSpectrum 1 % if set to zero, the tabulated spectrum is assumed to be normalized already in its amplitude to the starting redshift, otherwise this is recomputed based on the specified sigma8
ShapeGamma 0.21 % only needed for Efstathiou power spectrum
PrimordialIndex 1.0 % may be used to tilt the primordial index, primordial spectrum is k^PrimordialIndex
Seed 123456 % seed for IC-generator
NumFilesWrittenInParallel 1 % limits the number of files that are written in parallel when outputting
UnitLength_in_cm 3.085678e21 % defines length unit of output (in cm/h)
UnitMass_in_g 1.989e43 % defines mass unit of output (in g/cm)
UnitVelocity_in_cm_per_s 1e5 % defines velocity unit of output (in cm/sec)
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