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Hauptverfasser: Chen, Shi-Fan, Kokron, Nickolas
Format: Preprint
Veröffentlicht: 2023
Schlagworte:
Online-Zugang:https://arxiv.org/abs/2309.16761
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author Chen, Shi-Fan
Kokron, Nickolas
author_facet Chen, Shi-Fan
Kokron, Nickolas
contents We formulate the Lagrangian perturbation theory of galaxy intrinsic alignments and compute the resulting auto and cross power spectra of galaxy shapes, densities and matter to 1-loop order. Our model represents a consistent effective-theory description of galaxy shape including the resummation of long-wavelength displacements which damp baryon acoustic oscillations, and includes one linear, three quadratic and two cubic dimensionless bias coefficients at this order, along with counterterms and stochastic contributions whose structure we derive. We compare this Lagrangian model against the three-dimensional helicity spectra of halo shapes measured in N-body simulations by Akitsu et al (2023) and find excellent agreement on perturbative scales while testing a number of more restrictive bias parametrizations. The calculations presented are immediately relevant to analyses of both cosmic shear surveys and spectroscopic shape measurements, and we make a fast FFTLog-based code spinosaurus publicly available with this publication.
format Preprint
id arxiv_https___arxiv_org_abs_2309_16761
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle A Lagrangian theory for galaxy shape statistics
Chen, Shi-Fan
Kokron, Nickolas
Cosmology and Nongalactic Astrophysics
We formulate the Lagrangian perturbation theory of galaxy intrinsic alignments and compute the resulting auto and cross power spectra of galaxy shapes, densities and matter to 1-loop order. Our model represents a consistent effective-theory description of galaxy shape including the resummation of long-wavelength displacements which damp baryon acoustic oscillations, and includes one linear, three quadratic and two cubic dimensionless bias coefficients at this order, along with counterterms and stochastic contributions whose structure we derive. We compare this Lagrangian model against the three-dimensional helicity spectra of halo shapes measured in N-body simulations by Akitsu et al (2023) and find excellent agreement on perturbative scales while testing a number of more restrictive bias parametrizations. The calculations presented are immediately relevant to analyses of both cosmic shear surveys and spectroscopic shape measurements, and we make a fast FFTLog-based code spinosaurus publicly available with this publication.
title A Lagrangian theory for galaxy shape statistics
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2309.16761