Browsing Institutt for teoretisk astrofysikk by Author "Hagala, Robert"

Now showing items 1-6 of 6

  • Astrophysical Simulations for Uncovering Signatures of Gravity 
    Hagala, Robert (Doctoral thesis / Doktoravhandling, 2019)
    Einstein's theory of general relativity is currently our best model for how gravity works. It can be used to predict motions of planets, the speed-up of clocks on GPS satellites, and gravitational waves. General relativity ...
  • Cosmic tsunamis in modified gravity: disruption of screening mechanisms from scalar waves 
    Hagala, Robert; Llinares, Claudio; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Extending general relativity by adding extra degrees of freedom is a popular approach for explaining the accelerated expansion of the Universe and to build high energy completions of the theory of gravity. The presence of ...
  • Cosmological simulations with disformally coupled symmetron fields 
    Hagala, Robert (Master thesis / Masteroppgave, 2015)
    In this thesis, we investigate statistical properties of the redshift zero matter distribution in disformal gravity through N-body simulations. The disformal model studied here is a conformally coupled field in a symmetron ...
  • Non-linear dynamics of the minimal theory of massive gravity 
    Hagala, Robert; De Felice, Antonio; Mota, David; Mukohyama, Shinji (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    We investigate cosmological signatures of the minimal theory of massive gravity (MTMG). To this aim, we simulate the normal branch of the MTMG by employing the R AMSES N -body code and extending it with an effective ...
  • Non-linear phenomenology of disformally coupled quintessence 
    Llinares, Claudio; Hagala, Robert; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    The quintessence model is one of the simplest and better known alternatives to Einstein’s theory for gravity. The properties of the solutions have been studied in great detail in the background, linear and non-linear ...
  • The slingshot effect as a probe of transverse motions of galaxies 
    Hagala, Robert; Llinares, Claudio; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    Context: There are currently no reliable methods to measure the transverse velocities of galaxies. This is an important piece of information that is lacking in galaxy catalogues, and it could allow us to probe the physics ...