Morphological Signatures of Gravitational Evolution, Redshift-Space Distortions, and Massive Neutrinos in Large-Scale Structure

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Autori principali: Goyal, Priya, Appleby, Stephen, Chingangbam, Pravabati, Park, Changbom
Natura: Preprint
Pubblicazione: 2026
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author Goyal, Priya
Appleby, Stephen
Chingangbam, Pravabati
Park, Changbom
author_facet Goyal, Priya
Appleby, Stephen
Chingangbam, Pravabati
Park, Changbom
contents We investigate the morphological properties of large-scale structure in the Universe and the physical processes that modify the excursion-set morphology of the three-dimensional matter density field. Using the Quijote N-body simulation suite, we study how an initially Gaussian random matter density field is altered by non-linear gravitational evolution, redshift-space distortions, and massive neutrino free-streaming. To quantify these effects, we employ a comprehensive set of morphological descriptors, including Minkowski Functionals, Betti numbers, Minkowski Tensors, and local measures of the size and shape of connected components and cavities. We find that gravitational evolution, on quasi-linear scales $R_G \sim 10 h^{-1} \mathrm{Mpc}$, strongly skews the one-point distribution and slightly smooths the field via the merging of critical points, with a more pronounced effect for minima and wall saddle points than for peaks. Redshift-space distortions produce the strongest morphological signal, generating pronounced anisotropies that are robustly captured by Minkowski Tensors and local shape measures, arising from both coherent large-scale flows and non-linear Finger-of-God effects. In contrast, massive neutrinos induce an approximately isotropic suppression of small-scale structure, slightly reducing the amplitudes of the Minkowski Functionals while leaving individual shape measures largely unchanged. We further explore the sensitivity of these statistics to variations in cosmological parameters $Ω_m$, $n_s$, and $σ_8$, finding that they probe strongly degenerate combinations of $Ω_m$ and $n_s$, while also exhibiting sensitivity to $σ_8$ through the non-Gaussianity of the evolved density field.
format Preprint
id arxiv_https___arxiv_org_abs_2603_19734
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Morphological Signatures of Gravitational Evolution, Redshift-Space Distortions, and Massive Neutrinos in Large-Scale Structure
Goyal, Priya
Appleby, Stephen
Chingangbam, Pravabati
Park, Changbom
Cosmology and Nongalactic Astrophysics
We investigate the morphological properties of large-scale structure in the Universe and the physical processes that modify the excursion-set morphology of the three-dimensional matter density field. Using the Quijote N-body simulation suite, we study how an initially Gaussian random matter density field is altered by non-linear gravitational evolution, redshift-space distortions, and massive neutrino free-streaming. To quantify these effects, we employ a comprehensive set of morphological descriptors, including Minkowski Functionals, Betti numbers, Minkowski Tensors, and local measures of the size and shape of connected components and cavities. We find that gravitational evolution, on quasi-linear scales $R_G \sim 10 h^{-1} \mathrm{Mpc}$, strongly skews the one-point distribution and slightly smooths the field via the merging of critical points, with a more pronounced effect for minima and wall saddle points than for peaks. Redshift-space distortions produce the strongest morphological signal, generating pronounced anisotropies that are robustly captured by Minkowski Tensors and local shape measures, arising from both coherent large-scale flows and non-linear Finger-of-God effects. In contrast, massive neutrinos induce an approximately isotropic suppression of small-scale structure, slightly reducing the amplitudes of the Minkowski Functionals while leaving individual shape measures largely unchanged. We further explore the sensitivity of these statistics to variations in cosmological parameters $Ω_m$, $n_s$, and $σ_8$, finding that they probe strongly degenerate combinations of $Ω_m$ and $n_s$, while also exhibiting sensitivity to $σ_8$ through the non-Gaussianity of the evolved density field.
title Morphological Signatures of Gravitational Evolution, Redshift-Space Distortions, and Massive Neutrinos in Large-Scale Structure
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2603.19734