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We present and test a new method for the reconstruction of cosmological initial conditions from a full-sky galaxy catalogue. This method, called ZTRACE, is based on a self-consistent solution of the growing mode of gravitational…

Astrophysics · Physics 2009-10-31 P. Monaco , G. Efstathiou

We discuss the primordial nucleosynthesis in lepton asymmetric Universe models. In order to better estimate the universal baryon-mass density parameter $\Omega_b$, we try to remove the uncertainty from the theoretical prediction of…

Astrophysics · Physics 2007-05-23 T. Kajino , T. -K. Suzuki , S. Kawanomoto , H. Ando

We develop an analysis pipeline for characterizing the topology of large scale structure and extracting cosmological constraints based on persistent homology. Persistent homology is a technique from topological data analysis that quantifies…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-14 Matteo Biagetti , Alex Cole , Gary Shiu

This paper proposes a new framework to regularize the highly ill-posed and non-linear phase retrieval problem through deep generative priors using simple gradient descent algorithm. We experimentally show effectiveness of proposed algorithm…

Machine Learning · Computer Science 2018-08-20 Fahad Shamshad , Ali Ahmed

Near-field multiple-input multiple-output (MIMO) radar imaging systems have recently gained significant attention. In this paper, we develop novel non-iterative deep learning-based reconstruction methods for real-time near-field MIMO…

Image and Video Processing · Electrical Eng. & Systems 2023-12-29 Irfan Manisali , Okyanus Oral , Figen S. Oktem

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

Predicting the nonlinear evolution of cosmic structure from initial conditions is typically approached using Lagrangian, particle-based methods. These techniques excel in terms of tracking individual trajectories, but they might not be…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-11 Marion Ullmo , Nabila Aghanim , Aurélien Decelle , Miguel Aragon-Calvo

Weak lensing observations measure the shear field and hence the gradient of the dimensionless surface density $\kappa$. We present several new algorithms to recover $\kappa$ {}from shear estimates on a finite region and compare how they…

Astrophysics · Physics 2009-10-28 Gordon Squires , Nick Kaiser

Reconstructing the early Universe from the evolved present-day Universe is a challenging and computationally demanding problem in modern astrophysics. We devise a novel generative framework, Cosmo3DFlow, designed to address dimensionality…

Instrumentation and Methods for Astrophysics · Physics 2026-02-12 Md. Khairul Islam , Zeyu Xia , Ryan Goudjil , Jialu Wang , Arya Farahi , Judy Fox

The dissipation effects of primordial magnetic fields on the primordial elemental abundances were investigated. When a magnetic field reconnects, its energy is converted to the kinetic energy of charged particles, as observed for solar…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-23 Yini Lu , Motohiko Kusakabe

Deploying 3D single-photon Lidar imaging in real world applications faces several challenges due to imaging in high noise environments and with sensors having limited resolution. This paper presents a deep learning algorithm based on…

Image and Video Processing · Electrical Eng. & Systems 2023-07-25 Abderrahim Halimi , Jakeoung Koo , Stephen McLaughlin

A method is described to model the magnetic field in the vicinity of constellations of multiple satellites using field and plasma current measurements. This quadratic model has the properties that the divergence is zero everywhere and…

We analyze multi-bounce propagation of light in an unknown hidden volume and demonstrate that the reflected light contains sufficient information to recover the 3D structure of the hidden scene. We formulate the forward and inverse theory…

The cosmic curvature density parameter has been constrained in the present work independent of any background cosmological model. The reconstruction is performed adopting the non-parametric Gaussian Processes (GP). The constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-18 Purba Mukherjee , Narayan Banerjee

We study the inverse conductivity problem of how to reconstruct an isotropic electrical conductivity distribution $\gamma$ in an object from static electrical measurements on the boundary of the object. We give an exact reconstruction…

Functional Analysis · Mathematics 2007-05-23 Kim Knudsen , Alexandru Tamasan

The present thesis is devoted to the non-parametric reconstruction of some cosmological parameters using diverse observational datasets. The Universe is assumed to be spatially homogeneous and isotropic, thus described by the FLRW metric.…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-19 Purba Mukherjee

Hyperspectral neutron computed tomography enables 3D non-destructive imaging of the spectral characteristics of materials. In traditional hyperspectral reconstruction, the data for each neutron wavelength bin is reconstructed separately.…

Generating 3D scenes is a challenging open problem, which requires synthesizing plausible content that is fully consistent in 3D space. While recent methods such as neural radiance fields excel at view synthesis and 3D reconstruction, they…

Computer Vision and Pattern Recognition · Computer Science 2024-02-22 Titas Anciukevičius , Fabian Manhardt , Federico Tombari , Paul Henderson

We present PrimDiffusion, the first diffusion-based framework for 3D human generation. Devising diffusion models for 3D human generation is difficult due to the intensive computational cost of 3D representations and the articulated topology…

Computer Vision and Pattern Recognition · Computer Science 2023-12-08 Zhaoxi Chen , Fangzhou Hong , Haiyi Mei , Guangcong Wang , Lei Yang , Ziwei Liu

We propose a nonlinear filter for noise removal based on the Laplacian for 1D and 2D data. The method utilizes the solution to a fourth-order nonlinear PDE involving the Laplacian for data reconstruction. Evolution equations are introduced…

Numerical Analysis · Mathematics 2024-08-27 Nguyen S Hoang
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