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Line-of-sight distortions of the cosmic microwave background (CMB), including gravitational lensing, cosmic birefringence, and patchy screening, encode crucial cosmological information. While quadratic estimators (QE) have been excellent…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-06 Omar Darwish

We study the non-convex optimization landscape for maximum likelihood estimation in the discrete orbit recovery model with Gaussian noise. This model is motivated by applications in molecular microscopy and image processing, where each…

Statistics Theory · Mathematics 2021-03-02 Zhou Fan , Yi Sun , Tianhao Wang , Yihong Wu

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

Based on realistic simulations, we propose an hybrid method to reconstruct the lensing potential power spectrum, directly on PLANCK-like CMB frequency maps. It implies using a large galactic mask and dealing with a strong inhomogeneous…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 S. Plaszczynski , A. Lavabre , L. Perotto , J. -L. Starck

We present an iterative method to reconstruct the linear-theory initial conditions from the late-time cosmological matter density field, with the intent of improving the recovery of the cosmic distance scale from the baryon acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-05 Ryuichiro Hada , Daniel J. Eisenstein

We study the use of U-Nets in reconstructing the linear dark matter density field and its consequences for constraining cosmological parameters, in particular primordial non-Gaussianity. Our network is able to reconstruct the initial…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-23 Thomas Flöss , P. Daniel Meerburg

Future galaxy redshift surveys aim at probing the clustering of the cosmic large-scale structure with unprecedented accuracy, thus complementing cosmic microwave background experiments in the quest to deliver the most precise and accurate…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-03 Stefano Camera , Carmelita Carbone , Cosimo Fedeli , Lauro Moscardini

Integral field spectroscopy of high-redshift galaxies has become a powerful tool for understanding their dynamics and evolutionary states. However, in the case of gravitationally lensed systems, it has proved difficult to model both lensing…

Astrophysics of Galaxies · Physics 2022-04-13 Anthony J. Young , Charles R. Keeton , Andrew J. Baker

Taking into consideration of Kaniadakis entropy associated with the apparent horizon of Friedmann-Robertson-Walker (FRW) Universe and using the gravity-thermodynamics conjecture, a new cosmological scenarios emerges based on corrected…

General Relativity and Quantum Cosmology · Physics 2023-09-29 Amin Salehi

Measuring environment for large numbers of distant galaxies is still an open problem, for which we need galaxy positions and redshifts. Photometric redshifts are more easily available for large numbers of galaxies, but at the price of…

Astrophysics of Galaxies · Physics 2016-01-06 Nicola Malavasi , Lucia Pozzetti , Olga Cucciati , Sandro Bardelli , Andrea Cimatti

We present a cosmological hydrodynamical simulation of a representative volume of the Universe, as part of the Making Galaxies in a Cosmological Context (MaGICC) project. MaGICC uses a thermal implementation for supernova and early stellar…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-02 Rahul Kannan , Greg S. Stinson , Andrea V. Macciò , Chris Brook , Simone M. Weinmann , James Wadsley , H. M. P. Couchman

We develop a method of reconstructing the lensing field from lensed CMB temperature and polarization maps in real space as an alternative to the harmonic space estimators currently in use by extending an existing real space lensing…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-07 Heather Prince , Kavilan Moodley , Jethro Ridl , Martin Bucher

A key processing step in ground-based astronomy involves combining multiple noisy and blurry exposures to produce an image of the night sky with an improved signal-to-noise ratio. Typically, this is achieved via image coaddition, and can be…

Instrumentation and Methods for Astrophysics · Physics 2025-09-15 Yashil Sukurdeep , Tamás Budavári , Andrew J. Connolly , Fausto Navarro

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

Interpreting objects with basic geometric primitives has long been studied in computer vision. Among geometric primitives, superquadrics are well known for their ability to represent a wide range of shapes with few parameters. However, as…

Computer Vision and Pattern Recognition · Computer Science 2023-07-07 Weixiao Liu , Yuwei Wu , Sipu Ruan , Gregory S. Chirikjian

We describe the construction of an N-body simulation that mimics the true velocity and mass-density fields in a box of side 256\hmpc about the Local Group , and the production of mock catalogs that mimic in detail current catalogs of…

Astrophysics · Physics 2009-10-28 Tsafrir Kolatt , Avishai Dekel , Galit Ganon , Jeffrey Willick

Using the 37-point cosmic-chronometer subset of observational Hubble parameter (OHD) data, we develop a Bayesian Gaussian-process framework to reconstruct the normalized dark-energy density \(f(z)\) and equation of state \(w(z)\), focusing…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-14 Jia-yan Jiang , Wei Hong , Tong-jie Zhang

We apply the ZTRACE algorithm to the optical NOG and infra-red PSCz galaxy catalogues to reconstruct the pattern of primordial fluctuations that have generated our local Universe. We check that the density fields traced by the two…

Astrophysics · Physics 2009-11-07 Fabio Fontanot , Pierluigi Monaco , Stefano Borgani

We present ZEBRA, the Zurich Extragalactic Bayesian Redshift Analyzer. The current version of ZEBRA combines and extends several of the classical approaches to produce accurate photometric redshifts down to faint magnitudes. In particular,…

We constrain the parameters describing the kinematical state of the universe using a cosmographic approach, which is fundamental in that it requires a very minimal set of assumptions (namely to specify a metric) and does not rely on the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Vincenzo Vitagliano , Jun-Qing Xia , Stefano Liberati , Matteo Viel