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Halo bias links the statistical properties of the spatial distribution of dark matter halos to those of the underlying dark matter field, providing insights into clustering properties in both general relativity (GR) and modified-gravity…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-20 Jorge Enrique García-Farieta , Antonio D. Montero-Dorta , Andrés Balaguera-Antolínez

Many important challenges in science and technology can be cast as optimization problems. When viewed in a statistical physics framework, these can be tackled by simulated annealing, where a gradual cooling procedure helps search for…

Disordered Systems and Neural Networks · Physics 2024-01-17 Mohamed Hibat-Allah , Estelle M. Inack , Roeland Wiersema , Roger G. Melko , Juan Carrasquilla

We investigate the constraints on primordial non-Gaussianity with varied bispectrum shapes that can be derived from the power spectrum of galaxies and clusters of galaxies detected in future wide field optical/near-infrared surveys. Having…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Cosimo Fedeli , Carmelita Carbone , Lauro Moscardini , Andrea Cimatti

Local-type primordial non-Gaussianity (PNG), predicted by many non-minimal models of inflation, creates a scale-dependent contribution to the power spectrum of large-scale structure (LSS) tracers. Its amplitude is characterized by the…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-03 Boryana Hadzhiyska , Simone Ferraro

We compare reduced three-point correlations $Q$ of matter, haloes (as proxies for galaxies) and their cross correlations, measured in a total simulated volume of $\sim100 \ (h^{-1} \text{Gpc})^{3}$, to predictions from leading order…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-07 Kai Hoffmann , Enrique Gaztanaga , Roman Scoccimarro , Martin Crocce

We investigate nonlocal Lagrangian bias contributions involving gradients of the linear density field, for which we have predictions from the excursion set peak formalism. We begin by writing down a bias expansion which includes all the…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-30 Matteo Biagetti , Kwan Chuen Chan , Vincent Desjacques , Aseem Paranjape

Local primordial non-Gaussianity, parameterised as $f_{\rm NL}^{\rm local}$, will be stringently constrained using state-of-the-art methods applied to next-generation galaxy redshift survey data. In this paper, in preparation for the…

We study constraints on primordial mode-coupling from the power spectrum, squeezed-limit bispectrum and collapsed trispectrum of matter and halos. We describe these statistics in terms of long-wavelength $2$-point functions involving the…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-20 Roland de Putter

We measure the clustering of dark matter halos in a large set of collisionless cosmological simulations of the flat LCDM cosmology. Halos are identified using the spherical overdensity algorithm, which finds the mass around isolated peaks…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Jeremy L. Tinker , Brant E. Robertson , Andrey V. Kravtsov , Anatoly Klypin , Michael S. Warren , Gustavo Yepes , Stefan Gottlober

We construct a linear filter optimised for detecting dark-matter halos in weak-lensing data. The filter assumes a mean radial profile of the halo shear pattern and modifies that shape by the noise power spectrum. Aiming at separating…

Astrophysics · Physics 2009-11-10 M. Maturi , M. Meneghetti , M. Bartelmann , K. Dolag , L. Moscardini

We investigate the effect of primordial non-Gaussianities on halo number counts using N-body simulations with different values of $f_{\rm NL}^{\rm loc}$. We show how current theoretical models fail to adequately describe the non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-30 Luca Fiorino , Sofia Contarini , Federico Marulli , Ariel G. Sanchez , Marco Baldi , Andrea Fiorilli , Lauro Moscardini

Despite the Milky Way's proximity to us, our knowledge of its dark matter halo is fairly limited, and there is still considerable uncertainty in its halo mass. Many past techniques have been limited by assumptions such as the Galaxy being…

Astrophysics of Galaxies · Physics 2024-04-09 Elaheh Hayati , Peter Behroozi , Ekta Patel

We explore the biasing in the clustering statistics of halos as compared to dark matter (DM) in simulations. We look at the second and third order statistics at large scales of the (intermediate) MICEL1536 simulation and also measure…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Marc Manera , Enrique Gaztanaga

Primordial non-Gaussianity encodes valuable information about the physics of inflation, including the spectrum of particles and interactions. Significant improvements in our understanding of non-Gaussanity beyond Planck require information…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Jérôme Gleyzes , Roland de Putter , Daniel Green , Olivier Doré

We revisit the performance and biases of the two-dimensional approach to galaxy-galaxy lensing. This method exploits the information for the actual positions and ellipticities of source galaxies, rather than using only the ensemble…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-03 Andrej Dvornik , Sebastiaan L. Zoutendijk , Henk Hoekstra , Konrad Kuijken

We introduce a physically-motivated model of the matter power spectrum, based on the halo model and perturbation theory. This model achieves 1\% accuracy on all $k-$scales between $k=0.02h\,\mathrm{Mpc}^{-1}$ to $k=1h\,\mathrm{Mpc}^{-1}$.…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-01 Oliver H. E. Philcox , David N. Spergel , Francisco Villaescusa-Navarro

We study the matter bispectrum of large-scale structure by comparing the predictions of different perturbative and phenomenological models with the full three-dimensional bispectrum from $N$-body simulations estimated using modal methods.…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-20 Andrei Lazanu , Tommaso Giannantonio , Marcel Schmittfull , E. P. S. Shellard

Cosmological N-body simulations are crucial for understanding how the Universe evolves. Studying large-scale distributions of matter in these simulations and comparing them to observations usually involves detecting dense clusters of…

Astrophysics of Galaxies · Physics 2019-12-25 Aidan Reilly , Nikita Ivkin , Gerard Lemson , Vladimir Braverman , Alexander Szalay

Graph neural networks (GNNs) excel in modeling relational data such as biological, social, and transportation networks, but the underpinnings of their success are not well understood. Traditional complexity measures from statistical…

Machine Learning · Computer Science 2024-01-24 Cheng Shi , Liming Pan , Hong Hu , Ivan Dokmanić

We present a formal measure-theoretical theory of neural networks (NN) built on probability coupling theory. Our main contributions are summarized as follows. * Built on the formalism of probability coupling theory, we derive an algorithm…

Machine Learning · Computer Science 2018-12-03 Shuai Li
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