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The remarkable success in face forgery techniques has received considerable attention in computer vision due to security concerns. We observe that up-sampling is a necessary step of most face forgery techniques, and cumulative up-sampling…

Computer Vision and Pattern Recognition · Computer Science 2021-03-11 Honggu Liu , Xiaodan Li , Wenbo Zhou , Yuefeng Chen , Yuan He , Hui Xue , Weiming Zhang , Nenghai Yu

Assuming a fractal distribution of matter in the universe, consequences that follow from the General Theory of Relativity and the Copernican Principle for fractal cosmology are examined. The change in perspective necessary to deal with a…

Astrophysics · Physics 2007-05-23 A. K. Mittal , Daksh Lohiya

Photometric redshift estimation is an indispensable tool of precision cosmology. One problem that plagues the use of this tool in the era of large-scale sky surveys is that the bright galaxies that are selected for spectroscopic observation…

Instrumentation and Methods for Astrophysics · Physics 2017-07-18 Peter E. Freeman , Rafael Izbicki , Ann B. Lee

We present a rotation-equivariant unsupervised learning framework for the sparse deconvolution of non-negative scalar fields defined on the unit sphere. Spherical signals with multiple peaks naturally arise in Diffusion MRI (dMRI), where…

Image and Video Processing · Electrical Eng. & Systems 2021-02-19 Axel Elaldi , Neel Dey , Heejong Kim , Guido Gerig

Peculiar velocities induce apparent line of sight displacements of galaxies in redshift space, distorting the pattern of clustering in the radial versus transverse directions. On large scales, the amplitude of the distortion yields a…

Astrophysics · Physics 2015-06-24 A. J. S. Hamilton , M. Culhane

Photometric galaxy surveys probe the late-time Universe where the density field is highly non-Gaussian. A consequence is the emergence of the super-sample covariance (SSC), a non-Gaussian covariance term that is sensitive to fluctuations on…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-23 S. Gouyou Beauchamps , F. Lacasa , I. Tutusaus , M. Aubert , P. Baratta , A. Gorce , Z. Sakr

In recent years the possibility of measuring the temporal change of radial and transverse position of sources in the sky in real time have become conceivable thanks to the thoroughly improved technique applied to new astrometric and…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-26 Claudia Quercellini , Luca Amendola , Amedeo Balbi , Paolo Cabella , Miguel Quartin

Quantitative helio- and asteroseismology require very precise measurements of the frequencies, amplitudes, and lifetimes of the global modes of stellar oscillation. It is common knowledge that the precision of these measurements depends on…

Astrophysics · Physics 2009-11-13 Thorsten Stahn , Laurent Gizon

Cosmic shear requires high precision measurement of galaxy shapes in the presence of the observational Point Spread Function (PSF) that smears out the image. The PSF must therefore be known for each galaxy to a high accuracy. However, for…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 E. S. Cypriano , A. Amara , L. M. Voigt , S. L. Bridle , F. B. Abdalla , A. Refregier , M. Seiffert , J. Rhodes

We discuss in some details a novel algorithm for performing partial-sky spherical harmonic transforms (SHT), building on the Fourier-sphere method of Reinecke et al (2023) handling efficiently high numbers of arbitrary locations on the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-20 Julien Carron , Martin Reinecke

Beyond the linear regime, Fourier modes of cosmological random fields become correlated, and the power spectrum of density fluctuations contains only a fraction of the available cosmological information. To unveil this formerly hidden…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-25 M. Wolk , J. Carron , I. Szapudi

We introduce "anamorphic" cosmology, an approach for explaining the smoothness and flatness of the universe on large scales and the generation of a nearly scale-invariant spectrum of adiabatic density perturbations. The defining feature is…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-02 Anna Ijjas , Paul J. Steinhardt

Localised modelling error in the near-surface layers of evolutionary stellar models causes the frequencies of their normal modes of oscillation to differ from those of actual stars with matching interior structures. These frequency…

Solar and Stellar Astrophysics · Physics 2021-01-13 J. M. Joel Ong , Sarbani Basu , Jean M. McKeever

We present a new simple functional form to model the evolution of a spherical mass distribution in a cosmological context. Two parameters control the growth of the system and this is modelled using a redshift dependent exponential for the…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-19 Hans J. T. Buist , Amina Helmi

This article introduces an effective generalization of the polar flavor of the Fourier Theorem based on a new method of analysis. Under the premises of the new theory an ample class of functions become viable as bases, with the further…

Sound · Computer Science 2013-11-26 Sossio Vergara

The advent of the new generation of wide field galaxy surveys makes large N-body cosmological simulations a necessary evil. While the cosmological simulation codes have evolved a lot since the first calculations in the 80s, the…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-15 Claudio Llinares

Photometric redshift surveys map the distribution of matter in the Universe through the positions and shapes of galaxies with poorly resolved measurements of their radial coordinates. While a tomographic analysis can be used to recover some…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-06 David Alonso

Topological quantum matter exhibits a range of exotic phenomena when enriched by subdimensional symmetries. This includes new features beyond those that appear in the conventional setting of global symmetry enrichment. A recently discovered…

Strongly Correlated Electrons · Physics 2025-05-07 Po-Shen Hsin , David T. Stephen , Arpit Dua , Dominic J. Williamson

We review cosmological inference from optical and radio galaxy surveys, the X-Ray Background and the Cosmic Microwave Background. We focus on three topics: (i) First results from the 2dF galaxy redshift survey; (ii) Estimation of…

Astrophysics · Physics 2007-05-23 Ofer Lahav

In astronomical and cosmological studies one often wishes to infer some properties of an infinite-dimensional field indexed within a finite-dimensional metric space given only a finite collection of noisy observational data. Bayesian…

Instrumentation and Methods for Astrophysics · Physics 2014-06-26 Ewan Cameron
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