cosmology.py 文件源码

def growth_factor(self, z):
        """
        Growth factor at redshift z.

        References: Ref.[randall2002],Eq.(A7)
        """
        x0 = (2 * self.Ode0 / self.Om0) ** (1/3)
        x = x0 / (1 + z)
        coef = np.sqrt(x**3 + 2) / (x**1.5)
        integral = integrate.quad(lambda y: y**1.5 * (y**3+2)**(-1.5),
                                  a=0, b=x, epsabs=1e-5, epsrel=1e-5)[0]
        D = coef * integral
        return D