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We present an interpretable emulator for the linear matter power spectrum (MPS) in the standard cosmological model $\Lambda$CDM, constructed via a physics-informed symbolic regression framework. By combining domain knowledge with a machine…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-12 J. Bayron Orjuela-Quintana , Domenico Sapone , Savvas Nesseris

The Eulerian cosmological fluid equations are used to study the nonlinear mode coupling of density fluctuations. We evaluate the second-order power spectrum including all four-point contributions. In the weakly nonlinear regime we find that…

Astrophysics · Physics 2009-10-22 Bhuvnesh Jain , Edmund Bertschinger

We present Aletheia, a new emulator of the non-linear matter power spectrum, $P(k)$, built upon the evolution mapping framework. This framework addresses the limitations of traditional emulation by focusing on $h$-independent cosmological…

Upcoming experiments such as the SKA will provide huge quantities of data. Fast modelling of the high-redshift 21cm signal will be crucial for efficiently comparing these data sets with theory. The most detailed theoretical predictions…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-26 William D. Jennings , Catherine A. Watkinson , Filipe B. Abdalla , Jason D. McEwen

We discuss an extension of the Coyote emulator to predict non-linear matter power spectra of dark energy (DE) models with a scale factor dependent equation of state of the form w = w_0 + ( 1 - a )w_a . The extension is based on the mapping…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 L. Casarini , S. A. Bonometto , E. Tessarotto , P. -S. Corasaniti

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

Cosmology is poised to measure the neutrino mass sum $M_\nu$ and has identified several smaller-scale observables sensitive to neutrinos, necessitating accurate predictions of neutrino clustering over a wide range of length scales. The…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-21 Amol Upadhye , Juliana Kwan , Ian G. McCarthy , Jaime Salcido , Kelly R. Moran , Earl Lawrence , Yvonne Y. Y. Wong

We propose a new approximated expression for non-linear Dark Matter power spectrum much beyond BAO scales. The proposed expression agrees with the result of N-body simulation with the accuracy better than 2 % up to k=1.0 [h/Mpc] and k=0.7…

General Relativity and Quantum Cosmology · Physics 2012-12-03 Naonori S. Sugiyama , Toshifumi Futamase

We present N-body simulation calculations of the dependence of the power spectrum of non-linear cosmological mass density fluctuations on the equation of state of the dark energy, w=p/rho. At fixed linear theory power, increasing w leads to…

Astrophysics · Physics 2009-11-11 Patrick McDonald , Hy Trac , Carlo Contaldi

In this article, we argue that models based on machine learning (ML) can be very effective in estimating the non-linear matter power spectrum ($P(k)$). We employ the prediction ability of the supervised ML algorithms to build an estimator…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-17 Irshad Mohammed , Janu Verma

We have developed a fast method for predicting the angular power spectrum, C_l, of the cosmic microwave background given cosmological parameters and a primordial power spectrum of perturbations. After pre--computing the radiation…

Astrophysics · Physics 2009-11-07 Manoj Kaplinghat , Lloyd Knox , Constantinos Skordis

Near-future cosmological observations targeted at investigations of dark energy pose stringent requirements on the accuracy of theoretical predictions for the clustering of matter. Currently, N-body simulations comprise the only viable…

Astrophysics · Physics 2010-08-25 Katrin Heitmann , Martin White , Christian Wagner , Salman Habib , David Higdon

We present GokuNEmu, a ten-dimensional neural network emulator for the nonlinear matter power spectrum, designed to support next-generation cosmological analyses. Built on the Goku $N$-body simulation suite and the T2N-MusE emulation…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-12 Yanhui Yang , Simeon Bird , Ming-Feng Ho , Mahdi Qezlou

We use a suite of high-resolution $N$-body simulations and state-of-the-art perturbation theory to improve the code halofit, which predicts the nonlinear matter power spectrum. We restrict attention to parameters in the vicinity of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-09 Robert E. Smith , Raul E. Angulo

Future galaxy surveys will provide accurate measurements of the matter power spectrum across an unprecedented range of scales and redshifts. The analysis of these data will require one to accurately model the imprint of non-linearities of…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-11 Linda Blot , Pier-Stefano Corasaniti , Yann Rasera , Shankar Agarwal

We study in detail how neutrino perturbations can be followed in linear theory by using only terms up to $l=2$ in the Boltzmann hierarchy. We provide a new approximation to the third moment and demonstrate that the neutrino power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-15 Maria Archidiacono , Steen Hannestad

This paper presents simple analytic approximations to the linear power spectra, linear growth rates, and rms mass fluctuations for both components in a family of cold+hot dark matter (CDM+HDM) models that are of current cosmological…

Astrophysics · Physics 2009-10-28 Chung-Pei Ma

We derive constraints on cosmological parameters using the power spectrum of galaxy clustering measured from the final two-degree field galaxy redshift survey (2dFGRS) and a compilation of measurements of the temperature power spectrum and…

According to the Harrison-Zel'dovich prescription, the amplitude of matter density perturbations at horizon crossing is the same at all scales. Based on this prescription, we show how to construct the matter power spectrum of generic dark…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Iván Durán , Fernando Atrio-Barandela , Diego Pavón

We reconstruct the shape of the primordial power spectrum from the latest cosmic microwave background data, including the new results from the Wilkinson Microwave Anisotropy Probe (WMAP), and large scale structure data from the two degree…

Astrophysics · Physics 2009-11-07 S. L. Bridle , A. M. Lewis , J. Weller , G. Efstathiou