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Redshift space distortions of the matter density power spectrum carry information on the growth rate of cosmic structure but require accurate modeling of nonlinear and velocity effects on the density field. We test and advance the…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-19 Alberto Vallinotto , Eric V. Linder

We analytically model the non-linear effects induced by massive neutrinos on the total matter power spectrum using the halo model reaction framework of Cataneo et al. 2019. In this approach the halo model is used to determine the relative…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-21 Matteo Cataneo , J. D. Emberson , Derek Inman , Joachim Harnois-Deraps , Catherine Heymans

We describe an approximate statistical model for the sample variance distribution of the non-linear matter power spectrum that can be calibrated from limited numbers of simulations. Our model retains the common assumption of a multivariate…

In order to probe modifications of gravity at cosmological scales, one needs accurate theoretical predictions. N-body simulations are required to explore the non-linear regime of structure formation but are very time consuming. In this…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-24 Iñigo Sáez-Casares , Yann Rasera , Baojiu Li

We present a new approach to computing the matter density power spectrum, from large linear scales to small highly nonlinear scales. Instead of explicitly computing a partial series of high-order diagrams, as in perturbative resummation…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-17 Patrick Valageas , Takahiro Nishimichi , Atsushi Taruya

Observations of redshift-space distortions in spectroscopic galaxy surveys offer an attractive method for observing the build-up of cosmological structure. In this paper we develop and test a new statistic based on anisotropies in the…

Astrophysics · Physics 2009-11-13 Will J Percival , Martin White

Distances in cosmology are usually inferred from observed redshifts - an estimate that is dependent on the local peculiar motion - giving a distorted view of the three dimensional structure and affecting basic observables such as the…

Astrophysics · Physics 2008-12-18 J. Richard Shaw , Antony Lewis

Future galaxy clustering surveys will probe small scales where non-linearities become important. Since the number of modes accessible on intermediate to small scales is very high, having a precise model at these scales is important…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-04 Mona Jalilvand , Basundhara Ghosh , Elisabetta Majerotto , Benjamin Bose , Ruth Durrer , Martin Kunz

We allow for nonlinear effects in the likelihood analysis of galaxy peculiar velocities, and obtain ~35%-lower values for the cosmological density parameter Om and the amplitude of mass-density fluctuations. The power spectrum in the linear…

Astrophysics · Physics 2009-11-06 L. Silberman , A. Dekel , A. Eldar , I. Zehavi

A central challenge in precision cosmology with galaxy surveys is to extract non-Gaussian information from large-scale structure while controlling systematic uncertainties such as tracer bias. Conventional clustering statistics, such as the…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-27 Zhujun Jiang , Xu Xiao , Fenfen Yin , Xiao-Dong Li , Le Zhang

Current and future large scale structure surveys aim to constrain the neutrino mass and the equation of state of dark energy. We aim to construct accurate and interpretable symbolic approximations to the linear and nonlinear matter power…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-28 Ce Sui , Deaglan J. Bartlett , Shivam Pandey , Harry Desmond , Pedro G. Ferreira , Benjamin D. Wandelt

We embed linear and nonlinear parametrisations of beyond standard cosmological physics in the halo model reaction framework, providing a model-independent prescription for the nonlinear matter power spectrum. As an application, we focus on…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-18 B. Bose , M. Tsedrik , J. Kennedy , L. Lombriser , A. Pourtsidou , A. Taylor

A new method for estimating the angular power spectrum C_l from cosmic microwave background (CMB) maps is presented, which has the following desirable properties: (1) It is unbeatable in the sense that no other method can measure C_l with…

Astrophysics · Physics 2009-10-07 Max Tegmark

As the second component of SPARC (Simulation Package for Ab-initio Real-space Calculations), we present an accurate and efficient finite-difference formulation and parallel implementation of Density Functional Theory (DFT) for extended…

Computational Physics · Physics 2017-05-24 Swarnava Ghosh , Phanish Suryanarayana

Upcoming galaxy surveys will bring a wealth of information about the clustering of matter, but modeling small-scale structure beyond $\Lambda$CDM remains computationally challenging. While accurate N-body emulators exist to model the matter…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-10 João Rebouças , Victoria Lloyd , Jonathan Gordon , Guilherme Brando , Vivian Miranda

The measurements of the angular power spectrum of the Cosmic Microwave Background (CMB) anisotropy has proved crucial to the emergence of cosmology as a precision science in recent years. In this remarkable data rich period, the limitations…

Astrophysics · Physics 2007-05-23 Sanjit Mitra , Anand S. Sengupta , Tarun Souradeep

Constraining cosmological parameters from large-scale structure observations requires precise and accurate tools to compute its properties. While perturbation theory (PT) approaches can serve this purpose, exploration of large parameter…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-12 Ken Osato , Takahiro Nishimichi , Atsushi Taruya , Francis Bernardeau

Upcoming photometric lensing surveys will considerably tighten constraints on the neutrino mass and the dark energy equation of state. Nevertheless it remains an open question of how to optimally extract the information and how well the…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-12 Peter L. Taylor , Thomas D. Kitching , Jason D. McEwen

$ $Weak gravitational lensing is a powerful probe which is used to constrain the standard cosmological model and its extensions. With the enhanced statistical precision of current and upcoming surveys, high accuracy predictions for weak…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 Ting Tan , Dominik Zuercher , Janis Fluri , Alexandre Refregier , Federica Tarsitano , Tomasz Kacprzak

We describe a novel end-to-end approach using Machine Learning to reconstruct the power spectrum of cosmological density perturbations at high redshift from observed quasar spectra. State-of-the-art cosmological simulations of structure…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-21 Maria Han Veiga , Xi Meng , Oleg Y. Gnedin , Nickolay Y. Gnedin , Xun Huan