Résumé / Abstract Seminaire_IAP
« Tessellating the phase space of dark matter: A novel approach to visualizing, modeling and understanding the cosmic web  »

Sergei Shandarin
Physics Astron. Dept., Univ. Kansas (Lawrence, Kansas, Etats-Unis d'Amérique)

The Cosmic Web discovered in the last quarter of 20th century remains not fully understood. Even theoretical studies using realistic cosmological N-body simulations demonstrate noticeable perplexity in dealing with such features as multi-stream flows and caustics. This is despite the full dynamical information is easily available in the simulations. The majority of cosmologists probably would agree that the web consists of four geometrically distinct elements which are compact halos, filaments, walls aka pancakes, and voids.
However, it is unlikely the agreement would be reached even on the fractions of mass and volume occupied by each structural element of the Web and even less on its geometrical and topological characteristics. Seemingly contra-intuitive the easiest way to understanding three-dimensional geometry and topology of the Cosmic Web is probably via the study of its structure in the six-dimensional phase space. I will discuss the genesis and new developments in visualizing and modeling the Cosmic Web.
The new approach based on the tessellation of the dark matter phase-space sheet allows to compute the density and the other fields with a far greater spatial resolution than the currently used methods even from existing N-body simulations.
However the new technique may cause significant changes in the currently popular paradigm of the modeling of the Cosmic Web.
vendredi 23 novembre 2012 - 11:00
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
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