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We consider a wireless sensor network, sampling a bandlimited field, described by a limited number of harmonics. Sensor nodes are irregularly deployed over the area of interest or subject to random motion; in addition sensors measurements…

Other Computer Science · Computer Science 2009-11-13 A. Nordio , C. -F. Chiasserini , E. Viterbo

We present a method for reconstructing cosmological densityn for and velocity fields using the Lagrangian Zel'dovich formalism. . The method involves finding the least action solution for straight line particle paths in an evolving density…

Astrophysics · Physics 2015-06-24 R. A. C. Croft , E. Gaztanaga

We present a concept study on weak lensing map reconstruction through the cosmic magnification effect in galaxy number density distribution. We propose a minimal variance linear estimator to minimize both the dominant systematical and…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-16 Xinjuan Yang , Pengjie Zhang

We characterize the peculiar velocity field of the local large-scale structure reconstructed from the $2M++$ survey, by treating it as a fluid, extracting the divergence via different approximations over a range pf averaged scales. This…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-22 Erick Pastén , Sebastián Gálvez , Víctor Cárdenas

We focus on a multidimensional field with uncorrelated spectrum, and study the quality of the reconstructed signal when the field samples are irregularly spaced and affected by independent and identically distributed noise. More…

Information Theory · Computer Science 2009-11-13 A. Nordio , C-F. Chiasserini , E. Viterbo

The reconstruction of electrical current densities from magnetic field measurements is an important technique with applications in materials science, circuit design, quality control, plasma physics, and biology. Analytic reconstruction…

We investigate how well the 3D density field of neutral hydrogen in the Intergalactic Medium (IGM) can be reconstructed using the Lyman-alpha absorptions observed along lines of sight to quasars separated by arcmin distances in projection…

Astrophysics · Physics 2008-01-29 S. Caucci , S. Colombi , C. Pichon , E. Rollinde , P. Petitjean , T. Sousbie

A statistical method for reconstructing large scale structure behind the Zone of Avoidance is presented. It also corrects for shot-noise and for redshift distortion in galaxy surveys. The galaxy distribution is expanded in an orthogonal set…

Astrophysics · Physics 2007-05-23 Ofer Lahav

We study the nonlinear $E$-mode clustering in Lagrangian space by using large scale structure $N$-body simulations and use the displacement field information in Lagrangian space to recover the primordial linear density field. We find that,…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-28 Hao-Ran Yu , Ue-Li Pen , Hong-Ming Zhu

The late-time nonlinear Lagrangian displacement field is highly correlated with the initial field, so reconstructing it could enable us to extract primordial cosmological information. Our previous work [1] carefully studied the displacement…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-25 Atsuhisa Ota , Hee-Jong Seo , Shun Saito , Florian Beutler

Reconstructing the large scale density and velocity fields from surveys of galaxy distances, is a major challenge for cosmography. The data is very noisy and sparse. Estimated distances, and thereby peculiar velocities, are strongly…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-21 Aurélien Valade , Noam I Libeskind , Yehuda Hoffman , Simon Pfeifer

We apply an iterative reconstruction method to galaxy mocks in redshift space obtained from $N$-body simulations. Comparing the two-point correlation functions for the reconstructed density field, we find that although the performance is…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-26 Ryuichiro Hada , Daniel J. Eisenstein

We aim to construct a machine-learning approach that allows for a pixel-by-pixel reconstruction of the intergalactic medium (IGM) density field for various warm dark matter (WDM) models using the Lyman-alpha forest. With this regression…

Weak gravitational lensing is the slight distortion of galaxy shapes caused primarily by the gravitational effects of dark matter in the universe. In our work, we seek to invert the weak lensing signal from 2D telescope images to…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-22 Brandon Zhao , Aviad Levis , Liam Connor , Pratul P. Srinivasan , Katherine L. Bouman

We present MVSNeRF, a novel neural rendering approach that can efficiently reconstruct neural radiance fields for view synthesis. Unlike prior works on neural radiance fields that consider per-scene optimization on densely captured images,…

Computer Vision and Pattern Recognition · Computer Science 2021-08-25 Anpei Chen , Zexiang Xu , Fuqiang Zhao , Xiaoshuai Zhang , Fanbo Xiang , Jingyi Yu , Hao Su

Three-dimensional particle reconstruction with limited two-dimensional projections is an under-determined inverse problem that the exact solution is often difficult to be obtained. In general, approximate solutions can be obtained by…

Image and Video Processing · Electrical Eng. & Systems 2021-09-14 Qi Gao , Shaowu Pan , Hongping Wang , Runjie Wei , Jinjun Wang

Fitting half-integer generalized Laguerre functions to the evolved, real-space dark matter and halo correlation functions provides a simple way to reconstruct their initial shapes. We show that this methodology also works well in a wide…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-08 Farnik Nikakhtar , Ravi K. Sheth , Idit Zehavi

Generating geometric 3D reconstructions from Neural Radiance Fields (NeRFs) is of great interest. However, accurate and complete reconstructions based on the density values are challenging. The network output depends on input data, NeRF…

Computer Vision and Pattern Recognition · Computer Science 2023-09-27 Miriam Jäger , Boris Jutzi

We study the problem of reconstructing 3D feature curves of an object from a set of calibrated multi-view images. To do so, we learn a neural implicit field representing the density distribution of 3D edges which we refer to as Neural Edge…

Computer Vision and Pattern Recognition · Computer Science 2023-03-17 Yunfan Ye , Renjiao Yi , Zhirui Gao , Chenyang Zhu , Zhiping Cai , Kai Xu

Lagrangian reconstruction of large-scale peculiar velocity fields can be strongly affected by observational biases. We develop a thorough analysis of these systematic effects by relying on specially selected mock catalogues. For the purpose…

Astrophysics · Physics 2009-11-13 G. Lavaux , R. Mohayaee , S. Colombi , R. B. Tully , F. Bernardeau , J. Silk