Browsing Institutt for teoretisk astrofysikk by Author "Adamek, Julian"

Now showing items 1-3 of 3

  • A generic instability in clustering dark energy? 
    Hassani, Farbod; Adamek, Julian; Kunz, Martin; Shi, Pan; Wittwer, Peter (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    In this paper, we study the effective field theory (EFT) of dark energy (DE) for the k-essence model beyond linear order. Using particle-mesh N-body simulations that consistently solve the DE evolution on a grid, we find ...
  • Biased tracers as a probe of beyond-ΛCDM cosmologies 
    Hassani, Farbod; Adamek, Julian; Durrer, Ruth; Kunz, Martin (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Cosmological models beyond ΛCDM, such as those featuring massive neutrinos or modifications of gravity, often display a characteristic change (scale-dependent suppression or enhancement) in the matter power spectrum when ...
  • New nonlinear instability for scalar fields 
    Hassani, Farbod; Shi, Pan; Adamek, Julian; Kunz, Martin; Wittwer, Peter (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    In this Letter, we introduce the nonlinear partial differential equation ∂2τπ∝(→∇π)2 showing a new type of instability. Such equations appear in the effective field theory (EFT) of dark energy for the k-essence model as ...