Clustering dark energy imprints on cosmological observables of the gravitational field

Understand

We study cosmological observables on the past light cone of a fixed observer in the context of clustering dark energy.

• We focus on observables that probe the gravitational field directly, namely the integrated Sachs-Wolfe and non-linear Rees-Sciama effect (ISW-RS), weak gravitational lensing, gravitational redshift and Shapiro time delay.
• With our purpose-built $N$-body code "$k$-evolution" that tracks the coupled evolution of dark matter particles and the dark energy field, we are able to study the regime of low speed of sound $c_s$ where dark energy perturbations can become quite large.
• Using ray tracing we produce two-dimensional sky maps for each effect and we compute their angular power spectra.