Now showing items 1-2 of 2

  • Nonlinear modulation of the HI power spectrum on ultra-large scales. I 

    Umeh, Obinna; Maartens, Roy; Santos, Mario G. (IOP Science, 2015)
    Intensity mapping of the neutral hydrogen brightness temperature promises to provide a three-dimensional view of the universe on very large scales. Nonlinear effects are typically thought to alter only the small-scale ...
  • The observed galaxy bispectrum from single-field inflation in the squeezed limit 

    Koyama, Kazuya; Umeh, Obinna; Maartens, Roy; Bertacca, Daniele (IOP Publishing, 2018)
    Using the consistency relation in Fourier space, we derive the observed galaxy bispectrum from single- eld in ation in the squeezed limit, in which one of the three modes has a wavelength much longer than the other two. ...