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arXiv · 1706.04615

Quadratic genetic modifications: a streamlined route to cosmological simulations with controlled merger history

Martin P. Rey·Andrew Pontzen
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Abstract

Recent work has studied the interplay between a galaxy's history and its observable properties using "genetically modified" cosmological zoom simulations. The approach systematically generates alternative histories for a halo, while keeping its cosmological environment fixed. Applications to date altered linear properties of the initial conditions such as the mean overdensity of specified regions; we extend the formulation to include quadratic features such as local variance, which determines the overall importance of smooth accretion relative to mergers in a galaxy's history. We introduce an efficient algorithm for this new class of modification and demonstrate its ability to control the variance of a region in a one-dimensional toy model. Outcomes of this work are two-fold: (i) a clarification of the formulation of genetic modifications and (ii) a proof of concept for quadratic modifications leading the way to a forthcoming implementation in cosmological simulations.

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Martin P. Rey, Andrew Pontzen. 2017-11-01. Quadratic genetic modifications: a streamlined route to cosmological simulations with controlled merger history. https://doi.org/10.1093/mnras%2Fstx2744

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