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We develop perturbation theory approaches to model the marked correlation function constructed to up-weight low density regions of the Universe, which might help distinguish modified gravity models from the standard cosmology model based on…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-15 Alejandro Aviles , Kazuya Koyama , Jorge L. Cervantes-Cota , Hans A. Winther , Baojiu Li

The strong-coupling perturbation theory (SCPT) for correlated electron systems is extended to the case of full Coulomb interaction. The Coulomb mechanism of the orbital polarization is discussed and attention is paid to the importance of…

Strongly Correlated Electrons · Physics 2007-05-23 I. Sandalov , U. Lundin , O. Eriksson

The statistical tools needed to obtain a mass function from realistic collapse time estimates are presented. Collapse dynamics has been dealt with in paper I of this series by means of the powerful Lagrangian perturbation theory and the…

Astrophysics · Physics 2015-06-24 Pierluigi Monaco

Local nonlinear approximations to the growth of cosmic perturbations are developed, resulting in relations, at a given epoch, between the peculiar velocity and gravity fields and their gradients. Only the equation of motion is approximated,…

Astrophysics · Physics 2009-10-22 Paul J. Mancinelli , Amos Yahil

We present a simple method of generating approximate synthetic halo catalogues: HALOGEN. This method uses a combination of $2^{nd}$-order Lagrangian Perturbation Theory (2LPT) in order to generate the large-scale matter distribution,…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-08 Santiago Avila , Steven G. Murray , Alexander Knebe , Chris Power , Aaron S. G. Robotham , Juan Garcia-Bellido

Weak lensing by large scale structure induces correlated ellipticities in the images of distant galaxies. The two-point correlation is determined by the matter power spectrum along the line of sight. We use the fully nonlinear evolution of…

Astrophysics · Physics 2009-10-28 Bhuvnesh Jain , Uros Seljak

A previously proposed non-canonical coupled-perturbed Kohn-Sham density functional theory (KS-DFT)/Hartree-Fock (HF) treatment for spin-orbit coupling is here generalized to infinite periodic systems. The scalar-relativistic periodic…

In light of upcoming observations modelling perturbations in dark energy and modified gravity models has become an important topic of research. We develop an effective action to construct the components of the perturbed dark energy momentum…

High Energy Physics - Theory · Physics 2015-06-04 Richard A. Battye , Jonathan A. Pearson

We implement an adaptation of the COLA approach, a hybrid scheme that combines Lagrangian perturbation theory with an N-body approach, to model non-linear collapse in chameleon and symmetron modified gravity models. Gravitational screening…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-30 Georgios Valogiannis , Rachel Bean

Cosmological simulations of structure formation follow the collisionless evolution of dark matter starting from a nearly homogeneous field at early times down to the highly clustered configuration at redshift zero. The density field is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Francesca Iannuzzi , Klaus Dolag

The long-wavelength coherent overdensity and tidal force, which are not direct observables for a finite-volume survey, affect time evolution of cosmic structure formation and therefore clustering observables through the mode coupling. In…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-09 Shogo Masaki , Takahiro Nishimichi , Masahiro Takada

The augmented Lagrangian (AL) method that solves convex optimization problems with linear constraints has drawn more attention recently in imaging applications due to its decomposable structure for composite cost functions and empirical…

Optimization and Control · Mathematics 2015-11-30 Hung Nien , Jeffrey A. Fessler

This paper presents the preliminary results of the characterization of pattern evolution in the process of cosmic structure formation. We are applying on N-body cosmological simulations data the technique proposed by Rosa, Sharma & Valdivia…

Pattern Formation and Solitons · Physics 2009-11-11 Ana Paula Andrade , Andre Luis B. Ribeiro , Reinaldo R. Rosa

We design inexact proximal augmented Lagrangian based decomposition methods for convex composite programming problems with dual block-angular structures. Our methods are particularly well suited for convex quadratic programming problems…

Optimization and Control · Mathematics 2023-03-14 Kuang-Yu Ding , Xin-Yee Lam , Kim-Chuan Toh

We present a novel approach to generate higher-order initial conditions (ICs) for cosmological simulations that take into account the distinct evolution of baryons and dark matter. We focus on the numerical implementation and the validation…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-13 Oliver Hahn , Cornelius Rampf , Cora Uhlemann

Observations of redshift-space distortions in spectroscopic galaxy surveys offer an attractive method for observing the build-up of cosmological structure. In this paper we develop and test a new statistic based on anisotropies in the…

Astrophysics · Physics 2009-11-13 Will J Percival , Martin White

We study the nonlinear evolution of matter overdensities using the spherical collapse model in degenerate higher-order scalar-tensor (DHOST) theories beyond Horndeski, employing the effective field theory (EFT) of dark energy approach. We…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-18 Toshiki Takadera , Takashi Hiramatsu , Tsutomu Kobayashi

The present lecture notes address three columns on which the Lagrangian perturbation approach to cosmological dynamics is based: 1. the formulation of a Lagrangian theory of self--gravitating flows in which the dynamics is described in…

Astrophysics · Physics 2007-05-23 T. Buchert

N-body simulations are essential for understanding the formation and evolution of structure in the Universe. However, the discrete nature of these simulations affects their accuracy when modelling collisionless systems. We introduce a new…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-18 Oliver Hahn , Raul E. Angulo

Finding fast yet accurate numerical solutions to the Helmholtz equation remains a challenging task. The pollution error (i.e. the discrepancy between the numerical and analytical wave number k) requires the mesh resolution to be kept fine…

Numerical Analysis · Mathematics 2021-02-24 Vandana Dwarka , Roel Tielen , Matthias Möller , Kees Vuik