38 lines
778 B
Python
38 lines
778 B
Python
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import numpy as np
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import cosmolopy as cpy
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class CosmoGrowth:
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def __init__(self, **cosmo):
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self.cosmo = cosmo
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def D(self, a):
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return cpy.perturbation.fgrowth(1/a-1, self.cosmo['omega_M_0'], unnormed=True)
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def compute_E(self, a):
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om = self.cosmo['omega_M_0']
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ol = self.cosmo['omega_lambda_0']
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ok = self.cosmo['omega_k_0']
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E = np.sqrt(om/a**3 + ol + ok/a**2)
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H2 = -3*om/a**4 - 2*ok/a**3
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Eprime = 0.5*H2/E
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return E,Eprime
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def Ddot(self, a):
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E,Eprime = self.compute_E(a)
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D = self.D(a)
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Ddot_D = Eprime/E + 2.5 * self.cosmo['omega_M_0']/(a**3*E**2*D)
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Ddot_D *= a
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return Ddot_D
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def compute_velmul(self, a):
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E,_ = self.compute_E(a)
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velmul = self.Ddot(a)
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velmul *= 100 * a * E
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return velmul
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