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We present the integrated 3-point correlation functions (3PCF) involving both the cosmic shear and the galaxy density fields. These are a set of higher-order statistics that describe the modulation of local 2-point correlation functions…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-29 Anik Halder , Zhengyangguang Gong , Alexandre Barreira , Oliver Friedrich , Stella Seitz , Daniel Gruen

Non-Gaussian likelihoods, ubiquitous throughout cosmology, are a direct consequence of nonlinearities in the physical model. Their treatment requires Monte-Carlo Markov-chain or more advanced sampling methods for the determination of…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-24 Lennart Röver , Lea Carlotta Bartels , Björn Malte Schäfer

We present a study on the robustness of the covariance matrix estimation for galaxy clustering measurements depending on the cosmological parameters and galaxy bias. To this end, we have produced 9000 galaxy mock catalogues relying on the…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-22 Falk Baumgarten , Chia-Hsun Chuang

The estimation of cosmological constraints from observations of the large scale structure of the Universe, such as the power spectrum or the correlation function, requires the knowledge of the inverse of the associated covariance matrix,…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-04 Dante J. Paz , Ariel G. Sanchez

Starting with the density field equation of a self-gravity fluid in a static Universe, using the Schwinger functional differentiation technique, we derive the field equation of the 4-point correlation function (4PCF) of galaxies in the…

Astrophysics of Galaxies · Physics 2024-06-11 Yang Zhang , Shu-Guang Wu

Measurements of the peculiar velocities of large samples of galaxies enable new tests of the standard cosmological model, including determination of the growth rate of cosmic structure that encodes gravitational physics. With the size of…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-19 Chris Blake , Ryan J. Turner

We present a framework to compute non-Gaussian likelihoods for two-point correlation functions. The non-Gaussianity is most pronounced on large scales that will be well-measured by stage-IV weak-lensing surveys. We show how such a…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-09 Veronika Oehl , Tilman Tröster

Designing a covariance function that represents the underlying correlation is a crucial step in modeling complex natural systems, such as climate models. Geospatial datasets at a global scale usually suffer from non-stationarity and…

Machine Learning · Statistics 2015-07-10 Chintan A. Dalal , Vladimir Pavlovic , Robert E. Kopp

Recently isotropic basis functions of $N$ unit vector arguments were presented; these are of significant use in measuring the N-Point Correlation Functions (NPCFs) of galaxy clustering. Here we develop the generating function for these…

Instrumentation and Methods for Astrophysics · Physics 2024-11-20 Zachary Slepian , Jessica Chellino , Jiamin Hou

The three-point correlation function (3PCF) for galaxies provides an opportunity to measure the non-Gaussianity generated from nonlinear structure formation and also probes information about galaxy formation and evolution that is generally…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-30 Hong Guo , Cheng Li , Y. P. Jing , G. Börner

We report the measurement of the three-point correlation function (3PCF) of galaxies for the Las Campanas Redshift Survey (LCRS). We have not only measured the 3PCF in redshift space but also developed a method to measure the projected 3PCF…

Astrophysics · Physics 2009-10-30 Y. P. Jing , G. Boerner

We have performed a systematic study of the statistical behavior of non-Poissonian template fitting (NPTF), a method designed to analyze and characterize unresolved point sources in general counts datasets. In this paper, we focus on the…

Instrumentation and Methods for Astrophysics · Physics 2023-05-24 Luis Gabriel C. Bariuan , Tracy R. Slatyer

Angular cosmological correlators are infamously difficult to compute due to the highly oscillatory nature of the projection integrals. Motivated by recent development on analytic approaches to cosmological perturbation theory, in this paper…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-03 Hayden Lee , Cora Dvorkin

Small- and intermediate-scale galaxy clustering can be used to establish the galaxy-halo connection to study galaxy formation and evolution and to tighten constraints on cosmological parameters. With the increasing precision of galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-23 Zheng Zheng , Hong Guo

The nature of dark energy and the complete theory of gravity are two central questions currently facing cosmology. A vital tool for addressing them is the 3-point correlation function (3PCF), which probes deviations from a spatially random…

Making cosmological inferences from the observed galaxy clustering requires accurate predictions for the mean clustering statistics and their covariances. Those are affected by cosmic variance -- the statistical noise due to the finite…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-08 Anatoly Klypin , Francisco Prada , Joyce Byun

Context: Two-point correlation functions are used throughout cosmology as a measure for the statistics of random fields. When used in Bayesian parameter estimation, their likelihood function is usually replaced by a Gaussian approximation.…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-07 David Keitel , Peter Schneider

We investigate whether a Gaussian likelihood, as routinely assumed in the analysis of cosmological data, is supported by simulated survey data. We define test statistics, based on a novel method that first destroys Gaussian correlations in…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-15 Elena Sellentin , Alan F. Heavens

Accurate modelling of redshift-space distortions (RSD) is challenging in the non-linear regime for two-point statistics e.g. the two-point correlation function (2PCF). We take a different perspective to split the galaxy density field…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-14 Enrique Paillas , Yan-Chuan Cai , Nelson Padilla , Ariel Sánchez

The distribution of dark matter in the inner regions of galaxies poses a key challenge for small-scale {\Lambda}CDM cosmology. While cold dark matter simulations predict cuspy inner density profiles, observations of low surface brightness…

Astrophysics of Galaxies · Physics 2026-02-09 Sougata Sarkar , Prerana Biswas , Veselina Kalinova , Nirupam Roy , Narendra Nath Patra , Sushma Kurapati