primordial 0.0.4

primordial: inflationary equation solver

primordial:

inflationary equation solver

Author:

Will Handley

Version:

0.0.4

Homepage:

https://github.com/williamjameshandley/primordial

Documentation:

http://primordial.readthedocs.io/

Description

primordial is a python package for solving cosmological inflationary equations.

It is very much in beta stage, and currently being built for research purposes.

Example Usage

import matplotlib.pyplot as plt
from primordial.solver import Solver
from primordial.events import Inflation, Stationary
from primordial.t.equations import Equations, KD_initial_conditions
from primordial.potentials import ChaoticPotential
import numpy

fig, ax = plt.subplots(3,sharex=True)
for K in [-1, 0, +1]:
     m = 1
     V = ChaoticPotential(m)
     equations = Equations(K, V)

     events= [Inflation(equations, +1),                # Record inflation entry
              Inflation(equations, -1, terminal=True), # Stop on inflation exit
              Stationary(equations, terminal=True)]    # Stop if universe stops expanding


     solver = Solver(equations, events)

     N_p = -1.5
     phi_p = 23
     t = numpy.logspace(-5,10,1e6)

     y0 = KD_initial_conditions(t[0], N_p, phi_p, equations)

     sol = solver.solve(t, y0)

     ax[0].plot(sol.N,sol.phi)
     ax[0].set_ylabel(r'$\phi$')

     ax[1].plot(sol.N,sol.H)
     ax[1].set_yscale('log')
     ax[1].set_ylabel(r'$H$')

     ax[2].plot(sol.N,1/(sol.H*numpy.exp(sol.N)))
     ax[2].set_yscale('log')
     ax[2].set_ylabel(r'$1/aH$')

plt.show()