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Neural Operators (NOs) are a leading method for surrogate modeling of partial differential equations. Unlike traditional neural networks, which approximate individual functions, NOs learn the mappings between function spaces. While NOs have…

Astrophysics of Galaxies · Physics 2025-08-01 Keith Poletti , Stella S. R. Offner , Rachel A. Ward

We present a maximum-likelihood analysis of galaxy-galaxy lensing effects in galaxy clusters and in the field. The aim is to determine the accuracy and robustness of constraints that can be obtained on galaxy halo properties in both…

Astrophysics · Physics 2009-11-10 Marceau Limousin , Jean Paul Kneib , Priyamvada Natarajan

Optimization under uncertainty and risk is indispensable in many practical situations. Our paper addresses stability of optimization problems using composite risk functionals which are subjected to measure perturbations. Our main focus is…

Optimization and Control · Mathematics 2022-01-06 Darinka Dentcheva , Yang Lin , Spiridon Penev

For the first time, we develop a simulation-based model for the Minkowski functionals (MFs) of large-scale structure, which allows us to extract the full information available from the MFs (including both the Gaussian and non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-20 Wei Liu , Enrique Paillas , Carolina Cuesta-Lazaro , Georgios Valogiannis , Wenjuan Fang

In recent years forecasting activities have become a very important tool for designing and optimising large scale structure surveys. To predict the performance of such surveys, the Fisher matrix formalism is frequently used as a fast and…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-12 S. Yahia-Cherif , A. Blanchard , S. Camera , S. Ilić , K. Markovič , A. Pourtsidou , Z. Sakr , D. Sapone , I. Tutusaus

The structural and dynamic properties of the dark matter halos, though an important ingredient in understanding large-scale structure formation, require more conservative particle resolution than those required by halo mass alone in a…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-23 Sujatha Ramakrishnan , Premvijay Velmani

We use the highest-resolution FLAMINGO hydrodynamical simulation to quantify cosmic variance and large-scale coherence in the evolution of massive galaxies at high redshift. FLAMINGO combines a $(1\,\mathrm{cGpc})^3$ volume with baryonic…

Astrophysics of Galaxies · Physics 2025-11-14 Seunghwan Lim , Sandro Tacchella , Roberto Maiolino , Christopher C. Lovell , Joop Schaye

We use a set of hydrodynamical (Hydro) and dark matter only (DMonly) simulations to calibrate the halo mass function (HMF). We explore the impact of baryons, propose an improved parametrization for spherical overdensity masses and identify…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Sebastian Bocquet , Alex Saro , Klaus Dolag , Joseph J. Mohr

[ABRIDGED] The unconditional mass function (UMF) of dark matter haloes has been determined accurately in the literature, showing excellent agreement with high resolution numerical simulations. However, this is not the case for the…

Astrophysics · Physics 2009-11-13 J. A. Rubino-Martin , J. Betancort-Rijo , S. Patiri

We propose a versatile and accurate method to estimate the halo mass and concentration from the kinematics of satellite galaxies. We construct the 6D phase-space distribution function of satellites from a cosmological simulation based on…

Astrophysics of Galaxies · Physics 2019-12-02 Zhao-Zhou Li , Yong-Zhong Qian , Jiaxin Han , Wenting Wang , Y. P. Jing

Geometric flux-based Volume-of-Fluid (VOF) methods are widely considered consistent in handling two-phase flows with high density ratios. However, although the conservation of mass and momentum is consistent for two-phase incompressible…

Computational Physics · Physics 2025-01-08 Jun Liu , Tobias Tolle , Davide Zuzio , Jean-Luc Estivalezes , Santiago Marquez Damian , Tomislav Maric

Naive estimates of the statistics of large scale structure and weak lensing power spectrum measurements that include only Gaussian errors exaggerate their scientific impact. Non-linear evolution and finite volume effects are both…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-24 Emmanuel Schaan , Masahiro Takada , David N. Spergel

A long-standing issue in peculiar velocity cosmology is whether the halo/galaxy velocity bias $b_v=1$ at large scale. The resolution of this important issue must resort to high precision cosmological simulations. However, this is hampered…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-04 Junde Chen , Pengjie Zhang , Yi Zheng , Yu Yu , Yipeng Jing

We present a method for computing the 6-dimensional coarse-grained phase-space density $f(x,v)$ in an N-body system, and derive its distribution function $v(f)$. The method is based on Delaunay tessellation, where $v(f)$ is obtained with an…

Astrophysics · Physics 2009-11-10 I. Arad , A. Dekel , A. Klypin

In a serie of three papers, the dynamical interplay between environments and dark matter haloes is investigated, while focussing on the dynamical flows through their virial sphere. Our method relies on both cosmological simulations, to…

Astrophysics · Physics 2008-11-26 Dominique Aubert , Christophe Pichon

We formulate a data-driven method for constructing finite volume discretizations of a dynamical system's underlying Continuity / Fokker-Planck equation. A method is employed that allows for flexibility in partitioning state space,…

Fluid Dynamics · Physics 2023-04-10 Andre N. Souza

We recently developed a generalization of the halo model in order to describe the spatial clustering properties of each mass component in the Universe, including hot gas and stars. In this work we discuss the complementarity of the model…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 C. Fedeli , E. Semboloni , M. Velliscig , M. Van Daalen , J. Schaye , H. Hoekstra

Galaxy cluster counts have historically been important for the measurement of cosmological parameters and upcoming surveys will greatly reduce the statistical errors. To exploit the potential of current and future cluster surveys,…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-20 Roi Kugel , Joop Schaye , Matthieu Schaller , Victor J. Forouhar Moreno , Robert J. McGibbon

The purpose of this note is to clarify the effect of the finite size of spherical particles upon the characteristics of their spatial distribution through a random Poisson process (RPP). This information is of special interest when using…

Fluid Dynamics · Physics 2020-07-15 Markus Uhlmann

Simulating turbulent fluid flows is a computationally prohibitive task, as it requires the resolution of fine-scale structures and the capture of complex nonlinear interactions across multiple scales. This is particularly the case in direct…

Fluid Dynamics · Physics 2026-04-22 Ismaël Zighed , Nicolas Thome , Patrick Gallinari , Taraneh Sayadi