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Related papers: Reconstruction of primordial density fields

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The evolution of probability distribution functions (PDFs) of continuous density, velocity and velocity derivatives ( deformation tensor) fields in the theory of cosmological gravitational instability are considered. We show that in the…

Astrophysics · Physics 2007-05-23 Lev Kofman

We propose a new method to linearise cosmological mass density fields using higher order Lagrangian perturbation theory (LPT). We demonstrate that a given density field can be expressed as the sum of a linear and a nonlinear component which…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 F. S. Kitaura , R. E. Angulo

Detecting and measuring a non-Gaussian signature of primordial origin in the density field is a major science goal of next-generation galaxy surveys. The signal will permit us to determine primordial physics processes and constrain models…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Adam Andrews , Jens Jasche , Guilhem Lavaux , Fabian Schmidt

Optimal extraction of cosmological information from observations of the Cosmic Microwave Background critically relies on our ability to accurately undo the distortions caused by weak gravitational lensing. In this work, we demonstrate the…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-07 Thomas Flöss , William R. Coulton , Adriaan J. Duivenvoorden , Francisco Villaescusa-Navarro , Benjamin D. Wandelt

We revisit the issue of non-parametric gravitational lens reconstruction and present a new method to obtain the cluster mass distribution using strong lensing data without using any prior information on the underlying mass. The method…

Astrophysics · Physics 2009-10-07 J. M. Diego , P. Protopapas , H. B Sandvik , M. Tegmark

We present a cosmography analysis of the Local Universe based on the recently released Two-Micron All-Sky Redshift Survey (2MRS). Our method is based on a Bayesian Networks Machine Learning algorithm (the Kigen-code) which self-consistently…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-08 Francisco-Shu Kitaura , Pirin Erdogdu , Sebastian E. Nuza , Arman Khalatyan , Raul E. Angulo , Yehuda Hoffman , Stefan Gottloeber

We discuss the non--linear growth of the kurtosis of the smoothed peculiar velocity field (along an arbitrary direction), in an Einstein--de Sitter universe, induced by Gaussian primordial density fluctuations. Applying the perturbative…

Astrophysics · Physics 2008-11-26 Paolo Catelan , Lauro Moscardini

Understanding intricate magnetic structures in materials is essential for advancing materials science, spintronics, and geology. Recent developments of quantum-enabled magnetometers, such as nitrogen-vacancy (NV) centers in diamond, have…

Mesoscale and Nanoscale Physics · Physics 2025-12-12 Changyu Yao , Yue Yu , Yinyao Shi , Ji-In Jung , Zoltan Vaci , Yizhou Wang , Zhongyuan Liu , Chuanwei Zhang , Sonia Tikoo-Schantz , Chong Zu

We show how the Zel'dovich approximation and the second order displacement field of Lagrangian perturbation theory can be obtained from a general relativistic gradient expansion in \Lambda{}CDM cosmology. The displacement field arises as a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Cornelius Rampf , Gerasimos Rigopoulos

We present results for the cosmic non-linear density-fluctuation power spectrum based on the analytical formalism developed in [1] which allows us to study cosmic structure formation based on Newtonian particle dynamics in phase-space. This…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 Tristan Daus , Elena Kozlikin

We explore the possibility of putting constraints on dark energy models with statistical property of large scale structure in the non-linear region. In particular, we investigate the $w$ dependence of non-Gaussianity of the smoothed density…

Astrophysics · Physics 2010-10-27 Takayuki Tatekawa , Shuntaro Mizuno

We present the first suite of cosmological N-body simulations that simultaneously include the effects of two different and theoretically independent extensions of the standard $\Lambda$CDM cosmological scenario - namely an $f(R)$ theory of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Marco Baldi , Francisco Villaescusa-Navarro , Matteo Viel , Ewald Puchwein , Volker Springel , Lauro Moscardini

Knowledge of the primordial matter density field from which the large-scale structure of the Universe emerged over cosmic time is of fundamental importance for cosmology. However, reconstructing these cosmological initial conditions from…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-06 Oleg Savchenko , Guillermo Franco Abellán , Florian List , Noemi Anau Montel , Christoph Weniger

By revising the application of the open quantum system approach to the early universe and extending it to the conditions beyond the Markovian approximation, we obtain a new non-Markovian quantum Boltzmann equation. Throughout the paper, we…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-04 Moslem Zarei , Nicola Bartolo , Daniele Bertacca , Angelo Ricciardone , Sabino Matarrese

Surveys of the matter distribution contain `fossil' information on possible non-Gaussianity that is generated in the primordial Universe. This primordial signal survives only on the largest scales where cosmic variance is strongest. By…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-10 Sheean Jolicoeur , Roy Maartens , Simthembile Dlamini

Producing thousands of simulations of the dark matter distribution in the Universe with increasing precision is a challenging but critical task to facilitate the exploitation of current and forthcoming cosmological surveys. Many inexpensive…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-02 Davide Piras , Benjamin Joachimi , Francisco Villaescusa-Navarro

Adsorption is a relevant process in many fields, such as product manufacturing or pollution remediation in porous materials. Adsorption takes place at the molecular scale, amenable to be modeled by Lagrangian numerical methods. We have…

Machine Learning · Statistics 2020-04-15 Maryam Rahbaralam , Amir Abdollahi , Daniel Fernàndez-Garcia , Xavier Sanchez-Vila

I show how a renormalization group (RG) method can be used to incrementally integrate the information in cosmological large-scale structure data sets (including CMB, galaxy redshift surveys, etc.). I show numerical tests for Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-06 Patrick McDonald

In these lecture notes I review the theory of the non--linear evolution of cosmological perturbations in a self--gravitating collisionless medium, with vanishing vorticity. The problem is first analyzed in the context of the Newtonian…

Astrophysics · Physics 2015-06-24 Sabino Matarrese