English
Related papers

Related papers: Modeling iterative reconstruction and displacement…

200 papers

We present a direct approach to nonparametrically reconstruct the linear density field from an observed nonlinear map. We solve for the unique displacement potential consistent with the nonlinear density and positive definite coordinate…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-25 Hong-Ming Zhu , Yu Yu , Ue-Li Pen , Xuelei Chen , Hao-Ran Yu

We investigate the amount of primordial information that can be reconstructed from spectroscopic galaxy surveys, as well as what sets the noise in reconstruction at low wavenumbers, by studying a simplified universe in which galaxies are…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-23 Matthew McQuinn

We present a fast iterative FFT-based reconstruction algorithm that allows for non- parallel redshift-space distortions (RSD). We test our algorithm on both N-body dark matter simulations and mock distributions of galaxies designed to…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-17 Angela Burden , Will J. Percival , Cullan Howlett

A forward model of matter and biased tracers at arbitrary order in Lagrangian perturbation theory (LPT) is presented. The forward model contains the complete LPT displacement field at any given order in perturbations, as well as all…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-04 Fabian Schmidt

This text describes a method to simultaneously reconstruct flow states and determine particle properties from Lagrangian particle tracking (LPT) data. LPT is a popular measurement strategy for fluids in which particles in a flow are…

Fluid Dynamics · Physics 2023-11-16 Ke Zhou , Samuel J. Grauer

Potential features in the primordial power spectrum have been searched for in galaxy surveys in recent years since these features can assist in understanding the nature of inflation. The null detection to date suggests that any such…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-01 Yuhao Li , Hong-Ming Zhu , Baojiu Li

We present a new method to reconstruct the primordial (linear) density field using the estimated nonlinear displacement field. The divergence of the displacement field gives the reconstructed density field. We solve the nonlinear…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-23 Hong-Ming Zhu , Ue-Li Pen , Xuelei Chen

Spectroscopic redshift surveys are key tools to trace the large-scale structure (LSS) of the Universe and test the $\Lambda$CDM model. However, using redshifts as distance proxies introduces distortions in the 3D galaxy distribution. If…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-09 Edoardo Maragliano , Punyakoti Ganeshaiah Veena , Giulia Degni , Enzo Franco Branchini

We present a detailed analysis of a new, iterative density reconstruction algorithm. This algorithm uses a decreasing smoothing scale to better reconstruct the density field in Lagrangian space. We implement this algorithm to run on the…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-19 Xinyi Chen , Nikhil Padmanabhan

Reconstruction techniques are commonly used in cosmology to reduce complicated nonlinear behaviours to a more tractable linearized system. We study a new reconstruction technique that uses the Moving-Mesh algorithm to estimate the…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-21 Qiaoyin Pan , Ue-Li Pen , Derek Inman , Hao-Ran Yu

We examine the Lagrangian divergence of the displacement field, arguably a more natural object than the density in a Lagrangian description of cosmological large-scale structure. This quantity, which we denote \psi, quantifies the…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-17 Mark C. Neyrinck

We assess a neural network (NN) method for reconstructing 3D cosmological density and velocity fields (target) from discrete and incomplete galaxy distributions (input). We employ second-order Lagrangian Perturbation Theory to generate a…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-02 Punyakoti Ganeshaiah Veena , Robert Lilow , Adi Nusser

Herein, we present a deep-learning technique for reconstructing the dark-matter density field from the redshift-space distribution of dark-matter halos. We built a UNet-architecture neural network and trained it using the COmoving…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-21 Zitong Wang , Feng Shi , Xiaohu Yang , Qingyang Li , Yanming Liu , Xiaoping Li

Context: Analyzing the large-scale structure (LSS) with galaxy surveys demands accurate structure formation models. Such models should ideally be fast and have a clear theoretical framework to rapidly scan a variety of cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-08 F. -S. Kitaura , F. Sinigaglia , A. Balaguera-Antolínez , G. Favole

A theoretically interesting and practically important question in cosmology is the reconstruction of the initial density distribution provided a late-time density field. This is a long-standing question with a revived interest recently,…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-17 Yanlong Shi , Marius Cautun , Baojiu Li

Ultrasound reflection tomography is widely used to image large complex specimens that are only accessible from a single side, such as well systems and nuclear power plant containment walls. Typical methods for inverting the measurement rely…

Image and Video Processing · Electrical Eng. & Systems 2018-10-01 Hani Almansouri , S. V. Venkatakrishnan , Gregery T. Buzzard , Charles A. Bouman , Hector Santos-Villalobos

We make use of neural networks to accelerate the calculation of power spectra required for the analysis of galaxy clustering and weak gravitational lensing data. For modern perturbation theory codes, evaluation time for a single cosmology…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-11 Joseph DeRose , Shi-Fan Chen , Martin White , Nickolas Kokron

We derive a recursion relation in the framework of Lagrangian perturbation theory, appropriate for studying the inhomogeneities of the large scale structure of the universe. We use the fact that the perturbative expansion of the matter…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-27 Cornelius Rampf

Recently Eisenstein and collaborators introduced a method to `reconstruct' the linear power spectrum from a non-linearly evolved galaxy distribution in order to improve precision in measurements of baryon acoustic oscillations. We…

Astrophysics · Physics 2009-11-06 Nikhil Padmanabhan , Martin White , J. D. Cohn

Large scale structures provide valuable information of the primordial perturbations that encode the secrets of the origin of the Universe. It is an essential step to map between observables and their initial coordinates, called Lagrangian…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-10 Sijia Li , Ming-Jie Sheng , Haikun Li , Hao-Ran Yu