pyBBN v0.9.0: particles/DustParticle.py

#

Non-relativistic simplifications of density, energy density and pressure calculations

import numpy
import IntermediateParticle


name = 'dust'

#

Density

$\begin{equation} n = g \left(\frac{M T}{2 \pi}\right)^{3/2} e^{-\frac{M}{T}} \end{equation}$

def density(particle):

    return (
        particle.dof
        * numpy.sqrt(particle.mass * particle.T / 2. / numpy.pi)**3
        * numpy.exp(- particle.mass / particle.T)
    )

#

Energy density

$\begin{equation} \rho = n \left(M + \frac32 T\right) \end{equation}$

def energy_density(particle):

    return (particle.mass + 3./2. * particle.T) * density(particle)

#

Pressure

$\begin{equation} p = n T \end{equation}$

def pressure(particle):

    return density(particle) * particle.T

#

Master equation terms

Dust regime does not differ from intermediate regime here.

numerator = IntermediateParticle.numerator
denominator = IntermediateParticle.denominator