CosmoTransitions: Computing cosmological phase transition temperatures and bubble profiles with multiple fields

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• 作者：Carroll L. Wainwright ^{cwainwri@ucsc.edu}
• 关键词：Finite-temperature field theory ; Cosmology ; Phase transitions
• 刊名：Computer Physics Communications
• 出版年：2012
• 期刊代码：30_00104655
• 类别：cp
• 出版时间：September, 2012
• 卷：183
• 期：9
• 页码：2006-2013
• 文件大小：725 K

摘要

I present a numerical package (CosmoTransitions) for analyzing finite-temperature cosmological phase transitions driven by single or multiple scalar fields. The package analyzes the different vacua of a theory to determine their critical temperatures (where the vacuum energy levels are degenerate), their supercooling temperatures, and the bubble wall profiles which separate the phases and describe their tunneling dynamics. I introduce a new method of path deformation to find the profiles of both thin- and thick-walled bubbles. CosmoTransitions聽is freely available for public use.

Program summary

Program Title:聽CosmoTransitions

Catalogue identifier:聽AEML_v1_0

Program summary URL:聽

Program obtainable from:聽CPC Program Library, Queen鈥檚 University, Belfast, N. Ireland

Licensing provisions:聽Standard CPC licence,

No. of lines in distributed program, including test data, etc.:聽8775

No. of bytes in distributed program, including test data, etc.:聽621096

Distribution format:聽tar.gz

Programming language:聽Python.

Computer:聽Developed on a 2009 MacBook Pro. No computer-specific optimization was performed.

Operating system:聽Designed and tested on Mac OS X 10.6.8. Compatible with any OS with Python installed.

RAM:聽Approximately 50 MB, mostly for loading plotting packages.

Classification:聽1.9, 11.1.

External routines:聽SciPy, NumPy, matplotLib

Nature of problem:聽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:聽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鈥檚 minimum with respect to temperature.

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