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Related papers: The Coarse Geometry of Merger Trees in \Lambda CDM

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The excursion set approach uses the statistics of the density field smoothed on a wide range of scales, to gain insight into a number of interesting processes in nonlinear structure formation, such as cluster assembly, merging and…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-13 Marcello Musso , Ravi K. Sheth

Geometric graphs appear in many real-world data sets, such as road networks, sensor networks, and molecules. We investigate the notion of distance between embedded graphs and present a metric to measure the distance between two geometric…

Data Structures and Algorithms · Computer Science 2024-07-15 Erin Wolf Chambers , Elizabeth Munch , Sarah Percival , Xinyi Wang

When following the growth of structure in the Universe, we propose replacing merger trees with merger graphs, in which haloes can both merge and split into separate pieces. We show that this leads to smoother mass growth and eliminates…

Astrophysics of Galaxies · Physics 2020-05-11 William J. Roper , Peter A. Thomas , Chaichalit Srisawat

Merge trees are fundamental structures in topological data analysis. Interleaving distance is a widely accepted metric for comparing merge trees, with applications in visualization and scientific computing. While a greedy algorithm exists…

Computational Geometry · Computer Science 2025-09-22 Elena Farahbakhsh Touli , Talha Bin Masood

Distances on merge trees facilitate visual comparison of collections of scalar fields. Two desirable properties for these distances to exhibit are 1) the ability to discern between scalar fields which other, less complex topological…

Computational Geometry · Computer Science 2022-10-18 Brian Bollen , Pasindu Tennakoon , Joshua A. Levine

Although a fair amount of work has been devoted to growing Monte-Carlo merger trees which resemble those built from an N-body simulation, comparatively little effort has been invested in quantifying the caveats one necessarily encounters…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-03 D. Tweed , J. Devriendt , J. Blaizot , S. Colombi , A. Slyz

We study the growth of dark matter halos in the concordance LCDM cosmology using several N-body simulations of large cosmological volumes. We build merger trees from the Millennium and Millennium-II simulations, covering a range 10^9-10^15…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-21 Shy Genel , Nicolas Bouché , Thorsten Naab , Amiel Sternberg , Reinhard Genzel

In this work we study the interleaving distance between merge trees from a combinatorial point of view. We use a particular type of matching between trees to obtain a novel formulation of the distance. With such formulation, we tackle the…

Combinatorics · Mathematics 2024-11-11 Matteo Pegoraro

In scientific visualization, scalar fields are often compared through edit distances between their merge trees. Typical tasks include ensemble analysis, feature tracking and symmetry or periodicity detection. Tree edit distances represent…

Computational Geometry · Computer Science 2024-02-20 Florian Wetzels , Christoph Garth

We have used merger trees realizations to study the formation of dark matter haloes. The construction of merger-trees is based on three different pictures about the formation of structures in the Universe. These pictures include: the…

Astrophysics · Physics 2009-11-13 N. Hiotelis , A. Del Popolo

In the $\Lambda$CDM universe, structure formation is generally not a self-similar process, while some self-similarity remains in certain statistics which can greatly simplify our description and understanding of the cosmic structures. In…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-12 Wenkang Jiang , Jiaxin Han , Fuyu Dong , Feihong He

Merger trees track the evolution of halos across multiple snapshots. They assign for halos of a particular snapshot, the set of halos from previous snapshots they possibly originated from. In this work, Association rule analysis a well…

Instrumentation and Methods for Astrophysics · Physics 2017-01-18 B. Hareesh Gautham , Rahul Nigam

A halo merger tree forms the essential backbone of a semi-analytic model for galaxy formation and evolution. Recent studies have pointed out that extracting merger trees from numerical simulations of structure formation is non-trivial;…

The effects of spatial correlations of density fluctuations on merger histories of dark matter haloes (so-called `{\it merger trees}') are analysed. We compare the mass functions of dark haloes derived by a new method for calculating merger…

Astrophysics · Physics 2015-06-24 Masahiro Nagashima , Naoteru Gouda

The merging history of dark matter halos is computed with the Merging Cell Model proposed by Rodrigues & Thomas (1996). While originally discussed in the case of scale-free power spectra, it is developed and tested here in the framework of…

Astrophysics · Physics 2009-10-31 Barbara Lanzoni , Gary A. Mamon , Bruno Guiderdoni

Merger trees track the hierarchical assembly of dark matter halos across cosmic time and serve as essential inputs for semi-analytic models of galaxy formation. However, conventional methods for constructing merger trees rely on ad-hoc…

Astrophysics of Galaxies · Physics 2025-10-02 Tri Nguyen , Chirag Modi , Siddharth Mishra-Sharma , L. Y. Aaron Yung , Rachel S. Somerville

We study the properties of random walks on complex trees. We observe that the absence of loops reflects in physical observables showing large differences with respect to their looped counterparts. First, both the vertex discovery rate and…

Statistical Mechanics · Physics 2008-10-21 Andrea Baronchelli , Michele Catanzaro , Romualdo Pastor-Satorras

Accurate modeling of galaxy formation in a hierarchical, cold dark matter universe requires the use of sufficiently high-resolution merger trees to obtain convergence in the predicted properties of galaxies. When semi-analytic galaxy…

Astrophysics of Galaxies · Physics 2016-08-17 Andrew J. Benson , Chris Cannella , Shaun Cole

We construct merger trees of dark matter haloes and quantify their merger rates and mass growth rates using the joint dataset from the Millennium and Millennium-II simulations. The finer resolution of the Millennium-II Simulation has…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-26 Onsi Fakhouri , Chung-Pei Ma , Michael Boylan-Kolchin

Contour trees describe the topology of level sets in scalar fields and are widely used in topological data analysis and visualization. A main challenge of utilizing contour trees for large-scale scientific data is their computation at scale…

Computational Geometry · Computer Science 2024-10-01 Mingzhe Li , Hamish Carr , Oliver Rübel , Bei Wang , Gunther H. Weber