Discriminating Topology in Galaxy Distributions using Network Analysis

© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. The large-scale distribution of galaxies is generally analysed using the two-point correlation function. However, this statistic does not capture the topology of the distribution, and it is necessary...

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Main Authors: Hong, Sungryong, Coutinho, Bruno C, Dey, Arjun, Barabási, Albert-L, Vogelsberger, Mark, Hernquist, Lars, Gebhardt, Karl
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: Oxford University Press (OUP) 2021
Online Access:https://hdl.handle.net/1721.1/134452
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author Hong, Sungryong
Coutinho, Bruno C
Dey, Arjun
Barabási, Albert-L
Vogelsberger, Mark
Hernquist, Lars
Gebhardt, Karl
author2 Massachusetts Institute of Technology. Department of Physics
author_facet Massachusetts Institute of Technology. Department of Physics
Hong, Sungryong
Coutinho, Bruno C
Dey, Arjun
Barabási, Albert-L
Vogelsberger, Mark
Hernquist, Lars
Gebhardt, Karl
author_sort Hong, Sungryong
collection MIT
description © 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. The large-scale distribution of galaxies is generally analysed using the two-point correlation function. However, this statistic does not capture the topology of the distribution, and it is necessary to resort to higher order correlations to break degeneracies. We demonstrate that an alternate approach using network analysis can discriminate between topologically different distributions that have similar two-point correlations. We investigate two galaxy point distributions, one produced by a cosmological simulation and the other by a Lévy walk. For the cosmological simulation, we adopt the redshift z = 0.58 slice from Illustris and select galaxies with stellar masses greater than 108 M⊙. The two-point correlation function of these simulated galaxies follows a single power law, ζ(r) ~ r-1.5. Then, we generate Lévy walks matching the correlation function and abundance with the simulated galaxies. We find that, while the two simulated galaxy point distributions have the same abundance and two-point correlation function, their spatial distributions are very different; most prominently, filamentary structures, absent in Lévy fractals. To quantify these missing topologies, we adopt network analysis tools and measure diameter, giant component, and transitivity from networks built by a conventional friends-of-friends recipe with various linking lengths. Unlike the abundance and two-point correlation function, these network quantities reveal a clear separation between the two simulated distributions; therefore, the galaxy distribution simulated by Illustris is not a Lévy fractal quantitatively. We find that the described network quantities offer an efficient tool for discriminating topologies and for comparing observed and theoretical distributions.
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spelling mit-1721.1/1344522023-02-22T21:24:55Z Discriminating Topology in Galaxy Distributions using Network Analysis Hong, Sungryong Coutinho, Bruno C Dey, Arjun Barabási, Albert-L Vogelsberger, Mark Hernquist, Lars Gebhardt, Karl Massachusetts Institute of Technology. Department of Physics MIT Kavli Institute for Astrophysics and Space Research © 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. The large-scale distribution of galaxies is generally analysed using the two-point correlation function. However, this statistic does not capture the topology of the distribution, and it is necessary to resort to higher order correlations to break degeneracies. We demonstrate that an alternate approach using network analysis can discriminate between topologically different distributions that have similar two-point correlations. We investigate two galaxy point distributions, one produced by a cosmological simulation and the other by a Lévy walk. For the cosmological simulation, we adopt the redshift z = 0.58 slice from Illustris and select galaxies with stellar masses greater than 108 M⊙. The two-point correlation function of these simulated galaxies follows a single power law, ζ(r) ~ r-1.5. Then, we generate Lévy walks matching the correlation function and abundance with the simulated galaxies. We find that, while the two simulated galaxy point distributions have the same abundance and two-point correlation function, their spatial distributions are very different; most prominently, filamentary structures, absent in Lévy fractals. To quantify these missing topologies, we adopt network analysis tools and measure diameter, giant component, and transitivity from networks built by a conventional friends-of-friends recipe with various linking lengths. Unlike the abundance and two-point correlation function, these network quantities reveal a clear separation between the two simulated distributions; therefore, the galaxy distribution simulated by Illustris is not a Lévy fractal quantitatively. We find that the described network quantities offer an efficient tool for discriminating topologies and for comparing observed and theoretical distributions. 2021-10-27T20:05:04Z 2021-10-27T20:05:04Z 2016 2019-06-18T11:15:52Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/134452 Hong, S., et al. "Discriminating Topology in Galaxy Distributions Using Network Analysis." Monthly Notices of the Royal Astronomical Society 459 3 (2016): 2690-700. en 10.1093/MNRAS/STW803 Monthly Notices of the Royal Astronomical Society Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Oxford University Press (OUP) arXiv
spellingShingle Hong, Sungryong
Coutinho, Bruno C
Dey, Arjun
Barabási, Albert-L
Vogelsberger, Mark
Hernquist, Lars
Gebhardt, Karl
Discriminating Topology in Galaxy Distributions using Network Analysis
title Discriminating Topology in Galaxy Distributions using Network Analysis
title_full Discriminating Topology in Galaxy Distributions using Network Analysis
title_fullStr Discriminating Topology in Galaxy Distributions using Network Analysis
title_full_unstemmed Discriminating Topology in Galaxy Distributions using Network Analysis
title_short Discriminating Topology in Galaxy Distributions using Network Analysis
title_sort discriminating topology in galaxy distributions using network analysis
url https://hdl.handle.net/1721.1/134452
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