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Function fitting/approximation plays a fundamental role in computer graphics and other engineering applications. While recent advances have explored neural networks to address this task, these methods often rely on architectures with many…

Graphics · Computer Science 2025-05-28 Biao Zhang , Peter Wonka

We derive a minimal basis of kernels furnishing the perturbative expansion of the density contrast and velocity divergence in powers of the initial density field that is applicable to cosmological models with arbitrary expansion history,…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-14 Michael Hartmeier , Mathias Garny

Estimation of the angular power spectrum is one of the important steps in Cosmic Microwave Background (CMB) data analysis. Here, we present a nonparametric estimate of the temperature angular power spectrum for the Planck 2013 CMB data. The…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Amir Aghamousa , Arman Shafieloo , Mihir Arjunwadkar , Tarun Souradeep

Performing density functional theory (DFT) calculations requires a careful choice of computational parameters to ensure convergence and obtain meaningful results. This represents a particularly important problem for high-throughput and…

An accurate analytic approximation of the transfer function for the power spectra of primordial density perturbations in mixed dark matter models is presented. The fitting formula in a matter-dominated Universe ($\Omega_0=\Omega_M=1$) is a…

Astrophysics · Physics 2007-05-23 B. Novosyadlyj , R. Durrer , V. N. Lukash

Pinning down the total neutrino mass and the dark energy equation of state is a key aim for upcoming galaxy surveys. Weak lensing is a unique probe of the total matter distribution whose non-Gaussian statistics can be quantified by the…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-08 Aoife Boyle , Cora Uhlemann , Oliver Friedrich , Alexandre Barthelemy , Sandrine Codis , Francis Bernardeau , Carlo Giocoli , Marco Baldi

We derive and test an approximation for the angular power spectrum of galaxy number counts in the flat sky limit. The standard density and redshift space distortion (RSD) terms in the resulting approximation are distinct to the Limber…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-03 William L. Matthewson , Ruth Durrer

We present the BACCO project, a simulation framework specially designed to provide highly-accurate predictions for the distribution of mass, galaxies, and gas as a function of cosmological parameters. In this paper, we describe our main…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-04 Raul E. Angulo , Matteo Zennaro , Sergio Contreras , Giovanni Aricò , Marcos Pellejero-Ibañez , Jens Stücker

Standard cosmic microwave background (CMB) analyses constrain cosmological and astrophysical parameters by fitting parametric models to multifrequency power spectra (MFPS). However, such methods do not optimally weight maps in power…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-25 Kristen M. Surrao , J. Colin Hill

We present a further development of a method for accelerating the calculation of CMB power spectra, matter power spectra and likelihood functions for use in cosmological Bayesian inference. The algorithm, called {\sc CosmoNet}, is based on…

Astrophysics · Physics 2009-11-13 T. Auld , M. Bridges , M. P. Hobson

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

The rapidly increasing statistical power of cosmological imaging surveys requires us to reassess the regime of validity for various approximations that accelerate the calculation of relevant theoretical predictions. In this paper, we…

N-body simulations are the most powerful method to study the non-linear evolution of large-scale structure. However, they require large amounts of computational resources, making unfeasible their direct adoption in scenarios that require…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-14 Miguel Conceição , Alberto Krone-Martins , Antonio da Silva , Ángeles Moliné

Koopmans spectral functionals are a powerful extension of Kohn-Sham density-functional theory (DFT) that enable the prediction of spectral properties with state-of-the-art accuracy. The success of these functionals relies on capturing the…

Materials Science · Physics 2024-12-23 Yannick Schubert , Sandra Luber , Nicola Marzari , Edward Linscott

I present the Automated Line Fitting Algorithm, ALFA, a new code which can fit emission line spectra of arbitrary wavelength coverage and resolution, fully automatically. In contrast to traditional emission line fitting methods which…

Solar and Stellar Astrophysics · Physics 2016-01-20 Roger Wesson

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

The accuracy and effectiveness of Hermite spectral methods for the numerical discretization of partial differential equations on unbounded domains, are strongly affected by the amplitude of the Gaussian weight function employed to describe…

Numerical Analysis · Mathematics 2021-04-07 Lorella Fatone , Daniele Funaro , Gianmarco Manzini

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 present a new method to estimate redshift distributions and galaxy-dark matter bias parameters using correlation functions in a fully data driven and self-consistent manner. Unlike other machine learning, template, or correlation…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-09 Ben Hoyle , Markus Michael Rau

$ $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