7 papers
CLiENT: A new tool for emulating cosmological likelihoods using deep neural networks
Luca Janken, Steen Hannestad, Thomas Tram +1
Cosmological emulation of observables such as the Cosmic Microwave Background (CMB) spectra and matter power spectra have become increasingly common in recent years because of the…
Posterior sampling in the Age of Emulators
Andreas Nygaard, Luca Janken, Steen Hannestad +1
We investigate posterior sampling strategies for cosmological parameter inference using fully differentiable neural-network likelihood emulators, which provide both rapid likelihoo…
Self-interacting neutrinos in cosmological perturbation theory -- integrating the collision kernel
Jakob K. Mogensen, Steen Hannestad, Thomas Tram
Cosmological constraints on self-interacting neutrinos require a Boltzmann hierarchy in which the collision term is projected onto momentum-averaged multipoles. We revisit the coll…
CosmoSlider: An educational tool for cosmology
Andreas Nygaard, Steen Hannestad, Thomas Tram
Understanding how cosmological parameters influence the cosmic microwave background (CMB) power spectra is a central component of modern cosmology education, but interactive explor…
Cosmic curl -- Features and convergence of the vorticity power spectrum in -body simulations
Camilla T. G. Sørensen, Steen Hannestad, Thomas Tram
Observations of the cosmic velocity field could become an important cosmological probe in the near future. To take advantage of future velocity-flow surveys we must however have th…
Supernova and neutron-star limits on large extra dimensions reexamined
S. Hannestad, G. G. Raffelt
In theories with large extra dimensions, supernova (SN) cores are powerful sources of Kaluza-Klein (KK) gravitons. A large fraction of these massive particles are gravitationally r…