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Related papers: Power Spectrum Emulators from Neural Networks and …

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To investigate gravity in the non-linear regime of cosmic structure using measurements from Stage-IV surveys, it is imperative to accurately compute large-scale structure observables, such as non-linear matter power spectra, for gravity…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-09 Jiachen Bai , Junqing Xia

\textsc{DarkEmulator2} is a neural network emulator of the nonlinear matter power spectrum in a nine-dimensional $w_0 w_a \nu o \mathrm{CDM}$ parameter space, developed as the emulator component of the \textsc{Dark Quest II} (DQ2) program.…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-28 Satoshi Tanaka , Takahiro Nishimichi , Yosuke Kobayashi

We compare and validate COLA (COmoving Lagrangian Acceleration) simulations against existing emulators in the literature, namely Bacco and Euclid Emulator 2. Our analysis focuses on the non-linear response function, i.e., the ratio between…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-28 Guilherme Brando , Bartolomeo Fiorini , Kazuya Koyama , Hans A. Winther

Upcoming Large Scale Structure surveys aim to achieve an unprecedented level of precision in measuring galaxy clustering. However, accurately modeling these statistics may require theoretical templates that go beyond second-order…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-21 M. Icaza-Lizaola , Yong-Seon Song , Minji Oh , Yi Zheng

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

Interpreting observations of the Lyman-$\alpha$ forest flux power spectrum requires interpolation between a small number of expensive simulations. We present a Gaussian process emulator modelling the 1D flux power spectrum as a function of…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-17 Christian Pedersen , Andreu Font-Ribera , Keir K. Rogers , Patrick McDonald , Hiranya V. Peiris , Andrew Pontzen , Anže Slosar

We present a method to estimate non-Gaussian power spectrum covariance matrices by directly measuring the response of the small-scale power spectrum to long-wavelength perturbations via bispectrum and trispectrum estimators. Specifically,…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-21 Samuel Goldstein , Kendrick M. Smith , Utkarsh Giri , Moritz Münchmeyer

We present neural networks to generate redshift-space galaxy power spectrum multipoles for multiple tracer and redshift bins simultaneously given a set of input cosmology and galaxy bias parameters. This emulator utilizes a combination of…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-23 Joseph Adamo , Grace Gibbins , Anne Moore , Tim Eifler

We present a specific prescription for the calculation of cosmological power spectra, exploited here at two-loop order in perturbation theory (PT), based on the multi-point propagator expansion. In this approach power spectra are…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Atsushi Taruya , Francis Bernardeau , Takahiro Nishimichi , Sandrine Codis

We undertake the first comprehensive and quantitative real-space analysis of the cosmological information content in the environments of the cosmic web (voids, filaments, walls, and nodes) up to non-linear scales, $k = 0.5$ $h$/Mpc. Relying…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-25 Tony Bonnaire , Nabila Aghanim , Joseph Kuruvilla , Aurélien Decelle

We use the emulation framework CosmoPower to construct and publicly release neural network emulators of cosmological observables, including the Cosmic Microwave Background (CMB) temperature and polarization power spectra, matter power…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-06 Boris Bolliet , Alessio Spurio Mancini , J. Colin Hill , Mathew Madhavacheril , Hidde T. Jense , Erminia Calabrese , Jo Dunkley

We compute the two-loop effective field theory (EFT) power spectrum of dark matter density fluctuations in $\Lambda$CDM using the recently proposed COBRA method (Bakx. et al, 2025). With COBRA, we are able to evaluate the two-loop matter…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-11 Thomas Bakx , Henrique Rubira , Nora Elisa Chisari , Zvonimir Vlah

The 21 cm signal arising from fluctuations in the neutral hydrogen field, and its cross-correlation with other tracers of cosmic density, are promising probes of the high-redshift Universe. In this study, we assess the potential of the 21…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-26 Barun Maity

Cosmological neutrinos have their greatest influence in voids: these are the regions with the highest neutrino to dark matter density ratios. The marked power spectrum can be used to emphasize low density regions over high density regions,…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-13 Elena Massara , Francisco Villaescusa-Navarro , Shirley Ho , Neal Dalal , David N. Spergel

We improve the algorithm of Kosowsky, Milosavljevic, and Jimenez (2002) for computing power spectra of the cosmic microwave background. The present algorithm computes not only the temperature power spectrum but also the E-mode polarization…

Astrophysics · Physics 2009-11-10 Raul Jimenez , Licia Verde , Hiranya Peiris , Arthur Kosowsky

The information content of the minimum spanning tree (MST), used to capture higher-order statistics and information from the cosmic web, is compared to that of the power spectrum for a $\nu\Lambda$CDM model. The measurements are made in…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-10 Krishna Naidoo , Elena Massara , Ofer Lahav

We study the accuracy with which cosmological parameters can be determined from real space power spectrum of matter density contrast at weakly nonlinear scales using analytical approaches. From power spectra measured in $N$-body simulations…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-03 Ken Osato , Takahiro Nishimichi , Francis Bernardeau , Atsushi Taruya

We present $\texttt{matryoshka}$, a suite of neural network based emulators and accompanying Python package that have been developed with the goal of producing fast and accurate predictions of the nonlinear galaxy power spectrum. The suite…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-08 Jamie Donald-McCann , Florian Beutler , Kazuya Koyama , Minas Karamanis

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…

Accurate predictions for the non-linear matter power spectrum are needed to confront theory with observations in current and near future weak lensing and galaxy clustering surveys. We propose a computationally cheap method to create an…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-01 Hans Winther , Santiago Casas , Marco Baldi , Kazuya Koyama , Baojiu Li , Lucas Lombriser , Gong-Bo Zhao