title: CrasyDSE: A framework for solving Dyson-Schwinger equations.
abstract: Dyson-Schwinger equations are important tools for non-perturbative analyses of quantum field theories. For example, they are very useful for investigations in quantum chromodynamics and related theories. However, sometimes progress is impeded by the complexity of the equations. Thus automating parts of the calculations will certainly be helpful in future investigations. In this article we present a framework for such an automation based on aC++code that can deal with a large number of Green functions. Since also the creation of the expressions for the integrals of the Dyson-Schwinger equations needs to be automated, we defer this task to aMathematicanotebook. We illustrate the complete workflow with an example from Yang-Mills theory coupled to a fundamental scalar field that has been investigated recently. As a second example we calculate the propagators of pure Yang-Mills theory. Our code can serve as a basis for many further investigations where the equations are too complicated to tackle by hand. It also can easily be combined withDoFun, a program for the derivation of Dyson-Schwinger equations.
  Program title: CrasyDSECatalogue identifier: AEMY _v1_0Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEMY_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 49030No. of bytes in distributed program, including test data, etc.: 303958Distribution format: tar.gzProgramming language: Mathematica 8 and higher,C++.Computer: All on which Mathematica andC++are available.Operating system: All on which Mathematica andC++are available (Windows, Unix, Mac OS).Classification: 11.1, 11.4, 11.5, 11.6.Nature of problem: Solve (large) systems of Dyson-Schwinger equations numerically.Solution method: CreateC++functions in Mathematica to be used for the numeric code inC++. This code uses structures to handle large numbers of Green functions.Unusual features: Provides a tool to convert Mathematica expressions intoC++expressions including conversion of function names.Running time: Depending on the complexity of the investigated system solving the equations numerically can take seconds on a desktop PC to hours on a cluster.
authors.affiliation: Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstr. 2, 64289 Darmstadt, Germany.
authors.forename: Markus Q
authors.initials: MQ
authors.lastname: Huber
authors.affiliation: Institut für Physik, Karl-Franzens-Universität Graz, Universitätsplatz 5, 8010 Graz, Austria.
authors.forename: Mario
authors.initials: M
authors.lastname: Mitter
keywords: Correlation functions; Dyson–Schwinger equations; Quantum field theory