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Is gravitational growth responsible for the observed large scale structure in the universe? Do we need non-gaussian initial conditions or non-gravitational physics to explain the large scale features traced by galaxy surveys? I will briefly…

Astrophysics · Physics 2007-05-23 Enrique Gaztanaga

We study how to describe collapsed objects, such as galaxies, in the context of the Effective Field Theory of Large Scale Structures. The overdensity of galaxies at a given location and time is determined by the initial tidal tensor,…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-11 Leonardo Senatore

We numerically investigate the feasibility and limits of jointly estimating flow fields and unknown particle properties (e.g., position, size, and density) from Lagrangian particle tracking (LPT) data. LPT offers time-resolved, volumetric…

Fluid Dynamics · Physics 2026-05-26 Ke Zhou , Samuel J. Grauer

Reconstructing the density fluctuations in the early Universe that evolved into the distribution of galaxies we see today is a challenge of modern cosmology [ref.]. An accurate reconstruction would allow us to test cosmological models by…

Astrophysics · Physics 2015-06-24 Uriel Frisch , Sabino Matarrese , Roya Mohayaee , Andrei Sobolevski

Inflationary cosmology provides a successful paradigm for solving several problems, notably the generation of density perturbations which seed the formation of observed cosmic structure. We show how to use inverse scattering theory as the…

Astrophysics · Physics 2009-11-10 Salman Habib , Katrin Heitmann , Gerard Jungman

Redshift space distortions of the matter density power spectrum carry information on the growth rate of cosmic structure but require accurate modeling of nonlinear and velocity effects on the density field. We test and advance the…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-19 Alberto Vallinotto , Eric V. Linder

Recent Lyman-$\alpha$ forest tomography measurements of the intergalactic medium (IGM) have revealed a wealth of cosmic structures at high redshift ($z\sim 2.5$). In this work, we present the Tomographic Absorption Reconstruction and…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-18 Benjamin Horowitz , Khee-Gan Lee , Martin White , Alex Krolewski , Metin Ata

We propose RelitLRM, a Large Reconstruction Model (LRM) for generating high-quality Gaussian splatting representations of 3D objects under novel illuminations from sparse (4-8) posed images captured under unknown static lighting. Unlike…

Computer Vision and Pattern Recognition · Computer Science 2024-10-11 Tianyuan Zhang , Zhengfei Kuang , Haian Jin , Zexiang Xu , Sai Bi , Hao Tan , He Zhang , Yiwei Hu , Milos Hasan , William T. Freeman , Kai Zhang , Fujun Luan

We propose a new technique to measure the time delay of radio-loud gravitational lens systems, which does not rely on the excessive use of interferometric observations. Instead, the method is based on single-dish flux density monitoring of…

Astrophysics · Physics 2015-06-24 Bernhard Geiger , Peter Schneider

We investigate convergence of Lagrangian Perturbation Theory (LPT) by analyzing the model problem of a spherical homogeneous top-hat in an Einstein-deSitter background cosmology. We derive the formal structure of the LPT series expansion,…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-27 Sharvari Nadkarni-Ghosh , David F. Chernoff

We present a fast and accurate formulation for computing the nonlinear matter power spectrum at one-loop order based on Unified Lagrangian Perturbation Theory (ULPT). ULPT decomposes the density field into the Jacobian deviation, capturing…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-23 Naonori Sugiyama

We propose a new compressive imaging method for reconstructing 2D or 3D objects from their scattered wave-field measurements. Our method relies on a novel, nonlinear measurement model that can account for the multiple scattering phenomenon,…

Computer Vision and Pattern Recognition · Computer Science 2016-10-07 Hsiou-Yuan Liu , Ulugbek S. Kamilov , Dehong Liu , Hassan Mansour , Petros T. Boufounos

We present high--spatial resolution studies of the density field as predicted by Lagrangian perturbation approximations up to the third order. The first--order approximation is equivalent to the ``Zel'dovich approximation'' for the type of…

Astrophysics · Physics 2011-05-23 Thomas Buchert , Georgios Karakatsanis , Robert Klaffl , Peter Schiller

The reconstruction algorithm introduced by \cite{Eis07}, which is widely used in clustering analysis, is based on the inference of the first order Lagrangian displacement field from the Gaussian smoothed galaxy density field in redshift…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-09 M. Vargas-Magaña , S. Ho , S. Fromenteau , A. J. Cuesta

The Zeldovich approximation, 1st order Lagrangian perturbation theory, provides a good description of the clustering of matter and galaxies on large scales. The acoustic feature in the large-scale correlation function of galaxies imprinted…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Martin White

Galaxies are biased tracers of the underlying cosmic web, which is dominated by dark matter components that cannot be directly observed. Galaxy formation simulations can be used to study the relationship between dark matter density fields…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-19 Victoria Ono , Core Francisco Park , Nayantara Mudur , Yueying Ni , Carolina Cuesta-Lazaro , Francisco Villaescusa-Navarro

We present a general paradigm for dynamic 3D reconstruction from multiple independent and uncontrolled image sources having arbitrary temporal sampling density and distribution. Our graph-theoretic formulation models the Spatio-temporal…

Computer Vision and Pattern Recognition · Computer Science 2019-08-30 Xiangyu Xu , Enrique Dunn

We present a new analytic approach to describe large scale structure formation in the mildly non-linear regime. The central object of the method is the time-dependent probability distribution function generating correlators of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-09 Diego Blas , Mathias Garny , Mikhail M. Ivanov , Sergey Sibiryakov

Image-generative artificial intelligence (AI) has garnered significant attention in recent years. In particular, the diffusion model, a core component of generative AI, produces high-quality images with rich diversity. In this study, we…

Computer Vision and Pattern Recognition · Computer Science 2024-09-13 Sho Ozaki , Shizuo Kaji , Toshikazu Imae , Kanabu Nawa , Hideomi Yamashita , Keiichi Nakagawa

Dual-energy computed tomography (DECT) has shown great potential and promising applications in advanced imaging fields for its capabilities of material decomposition. However, image reconstructions and decompositions under sparse views…

Medical Physics · Physics 2016-08-01 Lei Li , Ailong Cai , Linyuan Wang , Bin Yan , Hanming Zhang , Zhizhong Zheng , Wenkun Zhang , Wanli Lu , Guoen Hu
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