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We apply the convolved Lagrangian perturbation theory (CLPT) formalism, in which one can express the matter density power spectrum in terms of integrals over a function of cumulants of the displacement field, allowing for a resummation of…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-14 Zvonimir Vlah , Uroš Seljak , Tobias Baldauf

We explore the Lagrangian perturbation theory (LPT) at 1-loop order with Gaussian initial conditions. We present an expansion method to approximately compute the power spectrum in LPT. Our approximate solution has good convergence in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Naonori S. Sugiyama

We investigate the purely spatial Lagrangian coordinate transformation from the Lagrangian to the basic Eulerian frame. We demonstrate three techniques for extracting the relativistic displacement field from a given solution in the…

General Relativity and Quantum Cosmology · Physics 2014-12-16 Cornelius Rampf , Alexander Wiegand

We develop a field-theoretic description of large-scale structure formation by taking the non-relativistic limit of a canonically transformed, real scalar field which is minimally coupled to scalar gravitational perturbations in…

General Relativity and Quantum Cosmology · Physics 2019-12-04 Pavel Friedrich , Tomislav Prokopec

This survey aims to investigate fundamental deep learning (DL) based 3D reconstruction techniques that produce photo-realistic 3D models and scenes, highlighting Neural Radiance Fields (NeRFs), Latent Diffusion Models (LDM), and 3D Gaussian…

Computer Vision and Pattern Recognition · Computer Science 2024-07-12 Yonge Bai , LikHang Wong , TszYin Twan

Accurate analyses of present and next-generation galaxy surveys require new ways to handle effects of non-linear gravitational structure formation in data. To address these needs we present an extension of our previously developed algorithm…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-15 Jens Jasche , Guilhem Lavaux

This paper focusses on the barely understood gap between the weakly nonlinear regime of structure formation and the onset of the virialized regime. While the former is accessed through perturbative calculations and the latter through…

Astrophysics · Physics 2007-05-23 Thomas Buchert

Modern galaxy surveys demand extensive survey volumes and resolutions surpassing current dark matter-only simulations' capabilities. To address this, many methods employ effective bias models on the dark matter field to approximate object…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-08 Daniel Forero-Sánchez , Francisco-Shu Kitaura , Francesco Sinigaglia , Jose María Coloma-Nadal , Jean-Paul Kneib

Improving the theoretical description of galaxy clustering on small scales is an important challenge in cosmology, as it can considerably increase the scientific return of forthcoming galaxy surveys -- e.g. tightening the bounds on neutrino…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-06 Marcos Pellejero-Ibanez , Jens Stuecker , Raul E. Angulo , Matteo Zennaro , Sergio Contreras , Giovanni Arico

We present a numerical study of the cosmic density vs. velocity divergence relation (DVDR) in the mildly non-linear regime. We approximate the dark matter as a non-relativistic pressureless fluid, and solve its equations of motion on a grid…

Astrophysics · Physics 2009-10-31 Andrzej Kudlicki , Michal Chodorowski , Tomasz Plewa , Michal Różyczka

We propose a new approach for reconstructing the 3D spatial distribution of small dislocation loops (DLs) from 2D TEM micrographs. This method is demonstrated for small DLs in tungsten, formed by low-dose ion-implantation, that appear as…

Materials Science · Physics 2018-04-04 Hongbing Yu , Xiaoou Yi , Felix Hofmann

The information about the mass density of galaxy clusters provided by the gravitational lens effect has inspired many inversion techniques. In this article, updates to the previously introduced method in Grale are described, and explored in…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-15 Jori Liesenborgs , Liliya L. R. Williams , Jenny Wagner , Sven De Rijcke

The reconstruction method was proposed more than a decade ago to boost the signal of baryonic acoustic oscillations measured in galaxy redshift surveys, which is one of key probes for dark energy. After moving the observed overdensities in…

In many scientific disciplines, we are interested in inferring the nonlinear dynamical system underlying a set of observed time series, a challenging task in the face of chaotic behavior and noise. Previous deep learning approaches toward…

Machine Learning · Computer Science 2022-07-07 Manuel Brenner , Florian Hess , Jonas M. Mikhaeil , Leonard Bereska , Zahra Monfared , Po-Chen Kuo , Daniel Durstewitz

Reconstructing the initial conditions of the Universe from late-time observations has the potential to optimally extract cosmological information. Due to the high dimensionality of the parameter space, a differentiable forward model is…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-19 Adrian E. Bayer , Chirag Modi , Simone Ferraro

This is a review paper on some of the physics, modeling, and iterative algorithms in proton computed tomography (pCT) image reconstruction. The primary challenge in pCT image reconstruction lies in the degraded spatial resolution resulting…

Medical Physics · Physics 2015-10-30 Scott Penfold , Yair Censor

Understanding a behavior of galaxy biasing is crucial for future galaxy redshift surveys. One aim is to measure the baryon acoustic oscillations (BAOs) within the precision of a few percent level. Using 30 large cosmological N-body…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-12 Masanori Sato , Takahiko Matsubara

We present a new formulation of Lagrangian perturbation theory which allows accurate predictions of the real- and redshift-space correlation functions of the mass field and dark matter halos. Our formulation involves a non-perturbative…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Jordan Carlson , Beth Reid , Martin White

Using recent advances in generative artificial intelligence (AI) brought by diffusion models, this paper introduces a new synergistic method for spectral computed tomography (CT) reconstruction. Diffusion models define a neural network to…

Reconstructing the mass density, velocity, and tidal (MTV) fields of dark matter from galaxy surveys is essential for advancing our understanding of the LSS of the Universe. In this work, we present a machine learning-based framework using…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-27 Feng Shi , Zitong Wang , Xiaohu Yang , Yizhou Gu , Chengliang Wei , Ming Li , Jiaxin Han , Zhejie Ding , Huiyuan Wang , Youcai Zhang , Wensheng Hong , Yirong Wang , Xiao-dong Li
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