xTras: A field-theory inspired xAct package for mathematica

We present the tensor computer algebra package xTras, which provides functions and methods frequently needed when doing (classical) field theory. Amongst others, it can compute contractions, make Ansätze, and solve tensorial equations. It is built upon the tensor computer algebra system xAct, a collection of packages for Mathematica.Program summaryProgram title: xTrasCatalogue identifier: AESH_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AESH_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: GNU General Public License, version 3No. of lines in distributed program, including test data, etc.: 155 879No. of bytes in distributed program, including test data, etc.: 565 389Distribution format: tar.gzProgramming language: Mathematica.Computer: Any computer running Mathematica 6 or newer.Operating system: Linux, Unix, Windows, OS X.RAM: 100 MbClassification: 5.External routines: xACT (www.xact.es)Subprograms used:Cat IdTitleReferenceAEBH_v1_0xPermCPC 179 (2008) 597ADZK_v2_0Invar Tensor Package 2.0CPC 179 (2008) 586Full-size tableTable optionsView in workspaceDownload as CSVNature of problem:Common problems in classical field theory: making Ansätze, computing contractions, solving tensorial equations, etc.Solution method:Various (group theory, brute-force, built-in Mathematica functions, etc.)Running time:1–60 s