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Intrinsically motivated artificial agents learn advantageous behavior without externally-provided rewards. Previously, it was shown that maximizing mutual information between agent actuators and future states, known as the empowerment…

Machine Learning · Computer Science 2021-05-11 Ruihan Zhao , Kevin Lu , Pieter Abbeel , Stas Tiomkin

The galaxy intrinsic alignment causes the galaxy ellipticity-ellipticity power spectrum between two photometric redshifts to decrease faster with respect to the redshift separation $\Delta z^P$, for fixed mean redshift. This offers a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Pengjie Zhang

We present a new estimation method for mapping the gravitational lensing potential from observed CMB intensity and polarization fields. Our method uses Bayesian techniques to estimate the average curvature of the potential over small local…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-23 Ethan Anderes , Lloyd Knox , Alexander van Engelen

We study the minimum volume ellipsoid estimator associates to a cloud of points in phase space. Using as a natural measure of uncertainty the symplectic capacity of the covariance ellipsoid we find that classical uncertainties obey…

Mathematical Physics · Physics 2015-05-19 Maurice de Gosson

Our goal is to improve the acceptance and angular resolution of VERITAS by implementing a camera image-fitting algorithm. Elliptical image parameters are extracted from 2D Gaussian distribution fits using a (chi)^2 minimization instead of…

Instrumentation and Methods for Astrophysics · Physics 2019-08-14 Jodi Christiansen

We introduce a new method for studying stochastic homogenization of elliptic equations in nondivergence form. The main application is an algebraic error estimate, asserting that deviations from the homogenized limit are at most proportional…

Analysis of PDEs · Mathematics 2019-12-10 Scott N. Armstrong , Charles K. Smart

This paper aims to build an estimate of an unknown density of the data with measurement error as a linear combination of functions from a dictionary. Inspired by the penalization approach, we propose the weighted Elastic-net penalized…

Statistics Theory · Mathematics 2020-07-07 Xiaowei Yang , Huiming Zhang , Haoyu Wei , Shouzheng Zhang

Hypoelliptic diffusion processes can be used to model a variety of phenomena in applications ranging from molecular dynamics to audio signal analysis. We study parameter estimation for such processes in situations where we observe some…

Methodology · Statistics 2007-10-30 Y. Pokern , A. M. Stuart , P. Wiberg

Cosmic shear holds great promise for a precision independent measurement of $\Omega\rm_m$, the mass density of the universe relative to the critical density. The signal is expected to be weak, so a thorough understanding of systematic…

Astrophysics · Physics 2008-11-26 S. Asztalos , W. H. de Vries , L. J Rosenberg , T. Treadway , D. Burke , C. Claver , A. Saha , P. Puxley

This paper addresses the challenge of probabilistic parameter estimation given measurement uncertainty in real-time. We provide a general formulation and apply this to pose estimation for an autonomous visual landing system. We present…

We show an efficient way to compute wide-angle or all-sky statistics of galaxy intrinsic alignment in three-dimensional configuration space. For this purpose, we expand the two-point correlation function using a newly introduced…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-05 Maresuke Shiraishi , Atsushi Taruya , Teppei Okumura , Kazuyuki Akitsu

We develop and apply the position angle-only shear estimator of Whittaker et al. (2014) to realistic galaxy images. This is done by demonstrating the method on the simulations of the GREAT3 challenge (Mandelbaum et al. 2014b), which include…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-21 Lee Whittaker , Michael L. Brown , Richard A. Battye

Image reconstruction methods based on deep neural networks have shown outstanding performance, equalling or exceeding the state-of-the-art results of conventional approaches, but often do not provide uncertainty information about the…

Computer Vision and Pattern Recognition · Computer Science 2020-12-01 Riccardo Barbano , Željko Kereta , Chen Zhang , Andreas Hauptmann , Simon Arridge , Bangti Jin

We extend the model-independent approach to characterise strong gravitational lenses of Wagner & Bartelmann (2016) to its most general form to leading order by using the orientation angles of a set of multiple images with respect to their…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-24 Jenny Wagner

Weak gravitational lensing provides a unique method to directly measure the distribution of mass in the universe. Because the distortions induced by lensing in the shape of background galaxies are small, the measurement of weak lensing…

Astrophysics · Physics 2009-11-06 Alexandre Refregier , David Bacon

Shear estimation bias from galaxy detection and blending identification is now recognized as an issue for ongoing and future weak lensing surveys. Currently, the empirical approach to correcting for this bias involves numerically shearing…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-29 Xiangchong Li , Rachel Mandelbaum

Likelihood analysis is typically limited to normally distributed noise due to the difficulty of determining the probability density function of complex, high-dimensional, non-Gaussian, and anisotropic noise. This is a major limitation for…

Instrumentation and Methods for Astrophysics · Physics 2023-06-14 Ronan Legin , Alexandre Adam , Yashar Hezaveh , Laurence Perreault Levasseur

We develop new solvability methods for divergence form second order, real and complex, elliptic systems above Lipschitz graphs, with $L_2$ boundary data. The coefficients $A$ may depend on all variables, but are assumed to be close to…

Analysis of PDEs · Mathematics 2010-09-16 Pascal Auscher , Andreas Axelsson

Different options can be used in order to measure the shear from observations in the context of weak lensing. Here we introduce new methods where the isotropy assumption for the distribution of the source galaxies is implemented directly on…

Astrophysics · Physics 2008-02-03 Marco Lombardi , Giuseppe Bertin

Measuring the angular clustering of galaxies as a function of redshift is a powerful method for extracting information from the three-dimensional galaxy distribution. The precision of such measurements will dramatically increase with…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Franz Elsner , Boris Leistedt , Hiranya V. Peiris
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