25 research outputs found

    Evaluating Sums over the Matsubara Frequencies

    Full text link
    Perturbative calculations in field theory at finite temperature involve sums over the Matsubara frequencies. Besides the usual difficulties that appear in perturbative computations, these sums give rise to some new obstacles that are carefully analized here. I present a fast and realible recipe to work out sums over the Matsubara frequencies. As this algorithm leads to deal with very cumbersome algebraic expressions, it has been written for computers by using the symbolic manipulation program Mathematica. It is also shown this algorithm to be self-consistent when it is applied to more than one loop computations.Comment: 10 page

    Junctions and thin shells in general relativity using computer algebra I: The Darmois-Israel Formalism

    Full text link
    We present the GRjunction package which allows boundary surfaces and thin-shells in general relativity to be studied with a computer algebra system. Implementing the Darmois-Israel thin shell formalism requires a careful selection of definitions and algorithms to ensure that results are generated in a straight-forward way. We have used the package to correctly reproduce a wide variety of examples from the literature. We present several of these verifications as a means of demonstrating the packages capabilities. We then use GRjunction to perform a new calculation - joining two Kerr solutions with differing masses and angular momenta along a thin shell in the slow rotation limit.Comment: Minor LaTeX error corrected. GRjunction for GRTensorII is available from http://astro.queensu.ca/~grtensor/GRjunction.htm

    Maple V release 2 notes

    No full text
    SIGLEAvailable from Comsol AG, Wabern-Bern (Switzerland) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
    corecore