Gravitating monopole and its black hole solution in Brans-Dicke theory

Takashi Tamaki, Keiichi Maeda, Takashi Torii

    Research output: Contribution to journalArticle

    17 Citations (Scopus)

    Abstract

    We find a self-gravitating monopole and its black hole solution in Brans-Dicke (BD) theory. We mainly discuss the properties of these solutions in the Einstein frame and compare the solutions with those in general relativity (GR) on the following points. From the field distributions of the generic type of self-gravitating monopole solutions, we find that the Yang-Mills potential and the Higgs field hardly depend on the BD parameter for most of the solution. There is an upper limit of the vacuum expectation value of the Higgs field to which a solution exists, as in GR. Since the BD scalar field has the effect of lessening an effective gauge charge, the upper limit in BD theory (in the ω=0 case) becomes about 30% larger than in GR. In some parameter ranges, there are two nontrivial solutions with the same mass, one of which can be regarded as the excited state of the other. This is confirmed by the analysis by catastrophe theory, which states that the excited solution is unstable. We also find that the BD scalar field varies more for solutions of smaller horizon radii, which can be understood from the differences of the nontrivial structure outside the horizon. A scalar mass and the thermodynamical properties of new solutions are also examined. Our analysis may give insight into solutions in other theories of gravity; particularly, a theory with a dilaton field may show similar effects because of its coupling to a gauge field.

    Original languageEnglish
    Pages (from-to)1-14
    Number of pages14
    JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
    Volume60
    Issue number10
    Publication statusPublished - 1999 Nov 15

    Fingerprint

    Monopole
    monopoles
    Black Holes
    General Relativity
    Higgs
    Scalar Field
    Horizon
    Catastrophe theory
    relativity
    Dilaton
    Yang-Mills
    Excited States
    Gauge Field
    Nontrivial Solution
    scalars
    Albert Einstein
    horizon
    Gauge
    Gravity
    Vacuum

    ASJC Scopus subject areas

    • Mathematical Physics
    • Physics and Astronomy(all)
    • Nuclear and High Energy Physics
    • Physics and Astronomy (miscellaneous)

    Cite this

    Gravitating monopole and its black hole solution in Brans-Dicke theory. / Tamaki, Takashi; Maeda, Keiichi; Torii, Takashi.

    In: Physical Review D - Particles, Fields, Gravitation and Cosmology, Vol. 60, No. 10, 15.11.1999, p. 1-14.

    Research output: Contribution to journalArticle

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