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We present simulations of a cosmic shear survey and show how the survey geometry influences the accuracy of determination of cosmological parameters. We numerically calculate the full covariance matrices Cov of two-point statistics of…

Astrophysics · Physics 2009-11-10 Martin Kilbinger , Peter Schneider

We present two related techniques to measure the two-point correlation function and the power spectrum with edge correction in any spatial dimensions. The underlying algorithm uses fast Fourier transforms for calculating the two-point…

Astrophysics · Physics 2009-11-11 István Szapudi , Jun Pan , Simon Prunet , Tamás Budavári

On some specified convex supporting sets of spheres, we find a generalized longitude function whose level sets are totally geodesic. Given an arbitrary (weakly) harmonic map into spheres, the composition of the generalized longitude…

Differential Geometry · Mathematics 2013-07-09 Ling Yang

This work aims to estimate 6Dof (6D) object pose in background clutter. Considering the strong occlusion and background noise, we propose to utilize the spatial structure for better tackling this challenging task. Observing that the 3D mesh…

Computer Vision and Pattern Recognition · Computer Science 2022-06-07 Jianhan Mei , Xudong Jiang , Henghui Ding

The statistics of large-scale structure are naturally described by power spectra in Fourier space. For fields on spatial hypersurfaces, translational invariance makes different Fourier modes uncorrelated and the power spectrum diagonal.…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-29 Chris Clarkson , Pritha Paul

Matrix-valued covariance functions are crucial to geostatistical modeling of multivariate spatial data. The classical assumption of symmetry of a multivariate covariance function is overlay restrictive and has been considered as unrealistic…

Statistics Theory · Mathematics 2017-11-28 Alfredo Alegría , Emilio Porcu , Reinhard Furrer

We develop a Bayesian hierarchical modelling approach for cosmic shear power spectrum inference, jointly sampling from the posterior distribution of the cosmic shear field and its (tomographic) power spectra. Inference of the shear power…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-11 Justin Alsing , Alan Heavens , Andrew H. Jaffe , Alina Kiessling , Benjamin Wandelt , Till Hoffmann

Owing to the mass-sheet degeneracy, cosmic shear maps do not probe directly the Fourier modes of the underlying mass distribution on scales comparable to the survey size and larger. To assess the corresponding effect on attainable…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Julien Carron , István Szapudi

Galaxy-galaxy weak lensing provides a powerful means of measuring the average matter distribution around lens galaxies -- i.e., the galaxy bias relation. Properly accounting for the spin-2 nature of weak lensing distortions, we develop a…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-28 Taisei Terawaki , Masahiro Takada , Takanori Taniguchi

We study the possibility of using quadrupole moments of auto-convolved galaxy images to measure cosmic shear. The autoconvolution of an image corresponds to the inverse Fourier transformation of its power spectrum. The new method has the…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-26 Xiangchong Li , Jun Zhang

A new three-dimensional model of the solar photosphere is presented in this paper and made publicly available to the community. This model has the peculiarity that it has been obtained by inverting spectro-polarimetric observations, rather…

Solar and Stellar Astrophysics · Physics 2015-05-27 H. Socas-Navarro

Estimation of the covariance structure of spatial processes is of fundamental importance in spatial statistics. In the literature, several non-parametric and semi-parametric methods have been developed to estimate the covariance structure…

Methodology · Statistics 2016-11-06 Shu Yang , Zhengyuan Zhu

Cosmic shear - the weak gravitational lensing effect generated by fluctuations of the gravitational tidal fields of the large-scale structure - is one of the most promising tools for current and future cosmological analyses. The…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-14 A. Spurio Mancini , P. L. Taylor , R. Reischke , T. Kitching , V. Pettorino , B. M. Schäfer , B. Zieser , Ph. M. Merkel

We report on two distinct computational approaches to self-consistently measure photospheric properties of large samples of stars. Both procedures consist of a set of several semi-integrated tasks based on shell and Python scripts, which…

Solar and Stellar Astrophysics · Physics 2013-09-04 Andre Milone , Ronaldo da Silva , Anne Sansom , Patricia Sanchez-Blazquez

We provide a fast algorithm to diagnose any directional dependence in the cosmological parameters by calculating maps of local cosmological parameter estimates and their joint errors. The technique implements a fast quadratic estimator…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-26 Suvodip Mukherjee , Benjamin D. Wandelt

We present growth of structure constraints from the cosmological analysis of the power spectrum multipoles of SDSS-III BOSS DR12 galaxies. We use the galaxy power spectrum model of Hand et al. (2017), which decomposes the galaxies into halo…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-03 Byeonghee Yu , Uros Seljak , Yin Li , Sukhdeep Singh

We propose a method to estimate non-Gaussian error bars on the matter power spectrum from galaxy surveys in the presence of non-trivial survey selection functions. The estimators are often obtained from formalisms like FKP and PKL, which…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Joachim Harnois-Deraps , Ue-Li Pen

In many applications data are measured or defined on a spherical manifold; spherical harmonic transforms are then required to access the frequency content of the data. We derive algorithms to perform forward and inverse spin spherical…

Astrophysics · Physics 2011-10-28 J. D. McEwen

I present an exact and explicit solution to the scalar (Stokes flux intensity) radio interferometer imaging equation on a spherical surface which is valid also for non-coplanar interferometer configurations. This imaging equation is…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 T. D. Carozzi

We derive spectral sum rules for inverse powers of the eigenvalues of the Helmholtz equation on a $d$-sphere in the presence of an arbitrary density. By adopting a rigorous renormalization scheme, we remove the divergent contributions of…

Mathematical Physics · Physics 2026-04-02 Paolo Amore