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A three-shape description the matter bispectrum of large-scale structure with and without primordial non-Gaussianity

Andrei Lazanu
Istituto Nazionale di Fisica Nucleare, Padova, Italy

I will present a comparison between theoretical models and numerical simulations for the matter bispectrum of large-scale structure at low redshifts. This comparison will highlight the advantages and shortcomings of the various perturbative and halo models; in particular I will show that there is a significant underprediction of the bispectrum of the standard halo model on intermediate scales for z>0.
Based on the shapes of these theoretical models and the N-body simualations, I will show how a simple phenomenological model based on the halo model, fitting the simulations very well, can be developed, as a sum of three simple shapes with scale-dependent amplitudes: the tree-level gravitational bispectrum, the squeezed shape and the constant shape.
I will also show how this model can be extended to primordial non-Gaussianity of the local and equilateral types.

2016 October 19, 13:30

Centro de Astrofísica da Universidade do Porto (Auditorium)
Rua das Estrelas, 4150-762 Porto

Faculdade de Ciências da Universidade de Lisboa Universidade do Porto Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Fundação para a Ciência e a Tecnologia COMPETE 2020 PORTUGAL 2020 União Europeia