Blar i Department of Mathematics and Natural Sciences på emneord "general relativity"

Viser treff 1-7 av 7

    • A spacetime not characterized by its invariants is of aligned type II 

      Hervik, Sigbjørn (Journal article; Peer reviewed, 2011)
      By using invariant theory we show that a (higher-dimensional) Lorentzian metric that is not characterised by its invariants must be of aligned type II; i.e., there exists a frame such that all the curvature tensors ...

    • All metrics have curvature tensors characterised by its invariants as a limit: the ϵ-property 

      Hervik, Sigbjørn (Journal article; Peer reviewed, 2011)
      We prove a generalisation of the ϵ-property, namely that for any dimension and signature, a metric which is not characterised by its polynomial scalar curvature invariants, there is a frame such that the components of the ...

    • Curvature operators and scalar curvature invariants 

      Hervik, Sigbjørn; Coley, Alan (Journal article; Peer reviewed, 2010)
      We continue the study of the question of when a pseudo-Riemannain manifold can be locally characterised by its scalar polynomial curvature invariants (constructed from the Riemann tensor and its covariant deriva- tives). ...

    • Discriminating the Weyl type in higher dimensions using scalar curvature invariants 

      Hervik, Sigbjørn; Coley, Alan (Journal article; Peer reviewed, 2011)
      We consider higher dimensional Lorentzian spacetimes which are currently of interest in theoretical physics. It is possible to algebraically classify any tensor in a Lorentzian spacetime of arbitrary dimensions using ...

    • Higher dimensional bivectors and classification of the Weyl operator 

      Hervik, Sigbjørn; Coley, Alan (Journal article; Peer reviewed, 2010)
      We develop the bivector formalism in higher dimensional Lorentzian spacetimes. We define the Weyl bivector operator in a manner consis- tent with its boost-weight decomposition. We then algebraically classify the Weyl ...

    • Pseudo-Riemannian VSI spaces 

      Hervik, Sigbjørn; Coley, Alan (Journal article; Peer reviewed, 2011)
      In this paper we consider pseudo-Riemannian spaces of arbitrary sig- nature for which all of their polynomial curvature invariants vanish (VSI spaces). We discuss an algebraic classification of pseudo-Riemannian spaces ...

    • Stability of anisotropic perfect fluid spheres with electrical charge when the cosmological constant is included 

      Ravndal, Arne (Masteroppgave/UIS-TN-IMN/2017;, Master thesis, 2017-06)
      The main task of this thesis is to investigate the stability of anisotropic perfect fluid spheres with electrical charge when the cosmological constant is included. However, before we get so far we needed to read articles ...