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As a major source of cosmological information, galaxy clustering is susceptible to long-wavelength density and tidal fluctuations. These long modes modulate the growth and expansion rate of local structures, shifting them in both amplitude…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-28 Yin Li , Marcel Schmittfull , Uroš Seljak

We investigate how unified models should be built to be able to predict the matter-density bispectrum (and power spectrum) from very large to small scales and that are at the same time consistent with perturbation theory at low $k$ and with…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Patrick Valageas , Takahiro Nishimichi

Stochastic resonance (SR) is a coherence enhancement effect due to noise that occurs in periodically-driven nonlinear dynamical systems. A very broad range of physical and biological systems present this effect such as climate change,…

Pattern Formation and Solitons · Physics 2021-06-08 Adriano A. Batista , A. A. Lisboa de Souza , Raoni S. N. Moreira

We investigate the building of unified models that can predict the matter-density power spectrum and the two-point correlation function from very large to small scales, being consistent with perturbation theory at low $k$ and with halo…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Patrick Valageas , Takahiro Nishimichi

Traditional variable selection methods could fail to be sign consistent when irrepresentable conditions are violated. This is especially critical in high-dimensional settings when the number of predictors exceeds the sample size. In this…

Methodology · Statistics 2022-04-26 Fei Xue , Annie Qu

Accurate inference of cosmology from weak lensing shear requires an accurate shear power spectrum covariance matrix. Here, we investigate this accuracy requirement and quantify the relative importance of the Gaussian (G), super-sample…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-20 Alexandre Barreira , Elisabeth Krause , Fabian Schmidt

We study the impact of different bias and redshift-space models on the halo power spectrum, quantifying their effect by comparing the fit to a subset of realizations taken from the WizCOLA suite. These provide simulated power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-16 Lucia Fonseca de la Bella , Donough Regan , David Seery , David Parkinson

We exploit a suite of large \emph{N}-body simulations (up to N=$4096^3$) performed with \Abacus, of scale-free models with a range of spectral indices $n$, to better understand and quantify convergence of the matter power spectrum. Using…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-30 Sara Maleubre , Daniel Eisenstein , Lehman H. Garrison , Michael Joyce

We present validation tests of emulator-based halo model method for cosmological parameter inference, assuming hypothetical measurements of the projected correlation function of galaxies, $w_{\rm p}(R)$, and the galaxy-galaxy weak lensing,…

The baryon acoustic oscillation (BAO) reconstruction plays a crucial role in cosmological analysis for spectroscopic galaxy surveys because it can make the density field effectively more linear and more Gaussian. The combination of the…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-10 Ruiyang Zhao , Kazuya Koyama , Yuting Wang , Gong-Bo Zhao

The spectrum and coherency are useful quantities for characterizing the temporal correlations and functional relations within and between point processes. This paper begins with a review of these quantities, their interpretation and how…

Biological Physics · Physics 2007-05-23 M. R. Jarvis , P. P. Mitra

We quantify the information content of the non-linear matter power spectrum, the halo mass function, and the void size function, using the Quijote $N$-body simulations. We find that these three statistics exhibit very different degeneracies…

We explore the connection between halo concentration and the dark matter power spectrum using the halo model. We fit halo model parameters to non-linear power spectra over a large range of cosmological models. We find that the non-linear…

Astrophysics · Physics 2008-11-26 Kevin M. Huffenberger , Uros Seljak

Future dark energy experiments will require better and more accurate theoretical predictions for the baryonic acoustic oscillations (BAO) signature in the spectrum of cosmological perturbations. Here, we use large N-body simulations of the…

In this work, using a NISQ framework, we obtain the gap of a BCS Hamiltonian. This could lead to interesting implications for superconductivity research. For such task, we choose to use the Variational Quantum Deflation and analyze the…

Quantum Physics · Physics 2022-12-02 Nahum Sá , Ivan S. Oliveira , Itzhak Roditi

Class imbalance remains a critical challenge in semi-supervised learning (SSL), especially when distributional mismatches between labeled and unlabeled data lead to biased classification. Although existing methods address this issue by…

Machine Learning · Computer Science 2025-11-25 Senmao Tian , Xiang Wei , Shunli Zhang

A software product line models the variability of highly configurable systems. Complete exploration of all valid configurations (the configuration space) is infeasible as it grows exponentially with the number of features in the worst case.…

Quantum Physics · Physics 2023-07-28 Joshua Ammermann , Tim Bittner , Domenik Eichhorn , Ina Schaefer , Christoph Seidl

We present a general method to compute the nonlinear matter power spectrum for dark energy and modified gravity scenarios with percent-level accuracy. By adopting the halo model and nonlinear perturbation theory, we predict the reaction of…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-16 Matteo Cataneo , Lucas Lombriser , Catherine Heymans , Alexander Mead , Alexandre Barreira , Sownak Bose , Baojiu Li

We describe in detail the general methodology and numerical implementation of consistent N-body simulations for coupled scalar field cosmological models, including the background cosmology and the generation of initial conditions (with the…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-04 Baojiu Li , John D. Barrow

Conservative mass limits are often imposed on the dark matter halo catalogues extracted from N-body simulations. By comparing simulations with different mass resolutions, at $z=0$ we find that even for halos resolved by 100 particles, the…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-08 Joaquin Armijo , Carlton M. Baugh , Nelson D. Padilla , Peder Norberg , Christian Arnold