On the road to percent accuracy VI: the nonlinear power spectrum for interacting dark energy with baryonic feedback and massive neutrinos

Accepted for publication in MNRAS

New paper led by Pedro Carrilho and Karim Carrion.

Understanding nonlinear structure formation is crucial for the full exploration of the data generated by forthcoming stage IV surveys, which will require accurate modelling of the matter power spectrum. This is particularly challenging for deviations from ΛCDM. We need to ensure that alternative cosmologies are well tested and avoid false detections. In this work we present an extension of the halo model reaction framework for interacting dark energy. We improve our predictions with the inclusion of baryonic feedback and massive neutrinos and search for degeneracies between the nonlinear effects of these two contributions and those of the dark sector interaction. By limiting the scales to those where our modelling is 1% accurate, we find a degeneracy between the effects of the interaction and those of baryonic feedback, but not with those generated by massive neutrinos. We expect the degeneracy with baryonic feedback to be resolvable when smaller scales are included. This work represents the first analytical tool for calculating the nonlinear matter power spectrum for coupled dark matter - dark energy models.

Alkistis Pourtsidou
Alkistis Pourtsidou
Associate Professor (Reader) in Theoretical Astrophysics