Description
One of the most pressing questions in modified gravity is how deviations from general relativity can manifest in upcoming galaxy surveys. This is especially relavant for theories exhibiting Vainshtein screening, which is known to be shape dependent: it is most effective around spherical sources, weaker around cylindrical sources and absent for planar sources. The cosmic web therefore offers a testing ground displaying many shapes in the form of clusters, filaments and walls. In this talk I will demonstrate how this shape dependence leaves an imprint on the matter bispectrum for a cubic galileon model conformally coupled to matter. This is obtained by exploiting second order cosmological perturbation theory and using the hi_class code for numerical results.
