The Peak/Dip Picture of the Cosmic Web

TL;DR

This paper introduces a new theoretical framework called the 'peak/dip picture' that models the formation of cosmic structures by considering local extrema of the density field, enhancing understanding of the cosmic web's morphology.

Contribution

It generalizes Doroshkevich's formalism to include correlations at density extrema and presents a novel peak/dip excursion-set-based algorithm for structure formation analysis.

Findings

The framework accounts for halo/void formation from density extrema.

The generalized formalism includes correlations between density Hessian and shear field.

Applications demonstrate improved modeling of cosmic web structures.

Abstract

The initial shear field plays a central role in the formation of large-scale structures, and in shaping the geometry, morphology, and topology of the cosmic web. We discuss a recent theoretical framework for the shear tensor, termed the `peak/dip picture', which accounts for the fact that halos/voids may form from local extrema of the density field - rather than from random spatial positions; the standard Doroshkevich's formalism is generalized, to include correlations between the density Hessian and shear field at special points in space around which halos/voids may form. We then present the `peak/dip excursion-set-based' algorithm, along with its most recent applications - merging peaks theory with the standard excursion set approach.