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Manuscript Title: CosmoTransitions: Computing Cosmological Phase Transition Temperatures and Bubble Profiles with Multiple Fields
Authors: Carroll L. Wainwright
Program title: CosmoTransitions
Catalogue identifier: AEML_v1_0
Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 183(2012)2006
Programming language: Python.
Computer: Developed on a 2009 MacBook Pro. No computer-specific optimization was performed.
Operating system: Designed and tested on Mac OS X 10.6.8. Compatible with any OS with Python installed.
RAM: Approximately 50 MB, mostly for loading plotting packages.
Keywords: Finite-temperature Field Theory, Cosmology, Phase Transitions.
Classification: 1.9, 11.1.

External routines: SciPy, NumPy, matplotLib

Nature of problem:
I describe a program to analyze early-Universe finite-temperature phase transitions with multiple scalar fields. The goal is to analyze the phase structure of an input theory, determine the amount of supercooling at each phase transition, and find the bubble-wall profiles of the nucleated bubbles that drive the transitions.

Solution method:
To find the bubble-wall profile, the program assumes that tunneling happens along a fixed path in field space. This reduces the equations of motion to one dimension, which can then be solved using the overshoot/undershoot method. The path iteratively deforms in the direction opposite the forces perpendicular to the path until the perpendicular forces vanish (or become very small).
To find the phase structure, the program finds and integrates the change in a phase's minimum with respect to temperature.

Running time:
Approximately 1 minute for full analysis of the two-scalar-field test model on a 2.5 GHz CPU.