English
Related papers

Related papers: AKRA 2.0: Accurate Kappa Reconstruction Algorithm …

200 papers

Deep neural networks have been the predominant paradigm in machine learning for solving cognitive tasks. Such models, however, are restricted by a high computational overhead, limiting their applicability and hindering advancements in the…

Machine Learning · Computer Science 2024-11-05 Ian Pons , Bruno Yamamoto , Anna H. Reali Costa , Artur Jordao

Interpolating scattered CFD datasets onto a uniform Cartesian grid can distort the true geometry, producing a convex-hull type envelope and activating nonphysical regions. This work presents a reconstruction framework that recovers…

Fluid Dynamics · Physics 2026-02-18 Mehran Sharifi , Gorka S. Larraona , Alejandro Rivas

We present an algorithm using Principal Component Analysis (PCA) to subtract galaxies from imaging data, and also two algorithms to find strong, galaxy-scale gravitational lenses in the resulting residual image. The combined method is…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 R. Joseph , F. Courbin , R. B. Metcalf , C. Giocoli , P. Hartley , N. Jackson , F. Bellagamba , J. -P. Kneib , L. Koopmans , G. Lemson , M. Meneghetti , G. Meylan , M. Petkova , S. Pires

In the era of synoptic surveys, the number of known gravitationally lensed quasars is set to increase by over an order of magnitude. These new discoveries will enable a move from single-quasar studies to investigations of statistical…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 N. F. Bate , C. J. Fluke

In the new perspective of spatial quantization, this article systematically studies the advantages of reconfigurable reflectarray (RRA) designed with closely spaced elements in terms of sidelobe level (SLL), scanning accuracy and scan loss,…

Applied Physics · Physics 2025-02-03 Xiaocun Zong , Fan Yang , Shenheng Xu , Maokun Li

Reconstruction of images from noisy linear measurements is a core problem in image processing, for which convex optimization methods based on total variation (TV) minimization have been the long-standing state-of-the-art. We present an…

Information Theory · Computer Science 2016-08-31 Jean Barbier , Eric W. Tramel , Florent Krzakala

We develop a method for general non-linear cluster lens reconstruction using the observable distortion of background galaxies. The distortion measures the combination $\gamma/(1-\kappa)$ of shear $\gamma$ and surface density $\kappa$. From…

Astrophysics · Physics 2009-10-22 Nick Kaiser

ALHAMBRA is a project to gather data to sample a fraction of the Universe with enough precision to follow the evolution of its content and properties with z, a kind of Cosmic Tomography. It is defined as a 4 square degrees photometric…

Purpose: Pushing MRI speed further demands more spatially-encoded information captured per unit time, e.g., by superimposing additional field modulations during oversampled readout. However, this can introduce calibration errors and…

Medical Physics · Physics 2026-01-12 Rui Tian , Martin Uecker , Oliver Holder , Pavel Povolni , Theodor Steffen , Klaus Scheffler

Optical spectra of galaxies and quasars from large cosmological surveys are used to measure redshifts and infer distances. They are also rich with information on the intrinsic properties of these astronomical objects. However, their…

Mixed-gas opacities are critical for radiative transfer in stellar and substellar atmospheres. Several approaches exist to obtain net k-coefficients for arbitrary mixtures, each trading accuracy against computational cost. I introduce a…

Earth and Planetary Astrophysics · Physics 2026-05-26 Elspeth K. H. Lee

We construct a pipeline for simulating weak lensing cosmology surveys with the Square Kilometre Array (SKA), taking as inputs telescope sensitivity curves; correlated source flux, size and redshift distributions; a simple ionospheric model;…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-26 Anna Bonaldi , Ian Harrison , Stefano Camera , Michael L. Brown

The AKARI All-Sky Catalogues are an important infrared astronomical database for next-generation astronomy that take over the IRAS catalog. We have developed an online service, AKARI Catalogue Archive Server (AKARI-CAS), for astronomers.…

Instrumentation and Methods for Astrophysics · Physics 2011-07-28 C. Yamauchi , S. Fujishima , N. Ikeda , K. Inada , M. Katano , H. Kataza , S. Makiuti , K. Matsuzaki , S. Takita , Y. Yamamoto , I. Yamamura

We present a new method, called $x$-cut cosmic shear, which optimally removes sensitivity to poorly modeled scales from the two-point cosmic shear signal. We show that the $x$-cut cosmic shear covariance matrix can be computed from the…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-19 Peter L. Taylor , Francis Bernardeau , Eric Huff

The Square Kilometre Array (SKA) will make ground breaking discoveries in pulsar science. In this chapter we outline the SKA surveys for new pulsars, as well as how we will perform the necessary follow-up timing observations. The SKA's wide…

Recent cosmic shear analyses have exhibited discrepancies of up to $1\sigma$ between the inferred cosmological parameters when analyzing summary statistics in real space versus harmonic space. In this paper, we demonstrate the consistent…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-23 Andy Park , Sukhdeep Singh , Xiangchong Li , Rachel Mandelbaum , Tianqing Zhang

Context. Weak gravitational lensing is a powerful probe of large-scale structure and cosmology. Most commonly, second-order correlations of observed galaxy ellipticities are expressed as a projection of the matter power spectrum,…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-25 Martin Kilbinger

Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) ideally requires a high spatial and high temporal resolution, but hardware limitations prevent acquisitions from simultaneously achieving both. Existing image reconstruction…

Signal Processing · Electrical Eng. & Systems 2025-11-18 Alexander J. Mertens , Hai-Ling Margaret Cheng

We derive exact reconstruction methods for cracks consisting of unions of Lipschitz hypersurfaces in the context of Calder\'on's inverse conductivity problem. Our first method obtains upper bounds for the unknown cracks, bounds that can be…

Analysis of PDEs · Mathematics 2024-05-24 Henrik Garde , Michael Vogelius

Enhanced modeling of microlensing variations in light curves of strongly lensed quasars improves measurements of cosmological time delays, the Hubble Constant, and quasar structure. Traditional methods for modeling extra-galactic…

Instrumentation and Methods for Astrophysics · Physics 2025-01-03 Somayeh Khakpash , Federica Bianco , Georgios Vernardos , Gregory Dobler , Charles Keeton