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Weak gravitational lensing from large-scale structure enhances and reduces the fluxes from extragalactic point sources with an rms amplitude of order 15%. In cosmic microwave background (CMB) experiments, sources exceeding some flux…

Astrophysics · Physics 2015-06-24 Max Tegmark , Jens Villumsen

We present preliminary results from our on-going study: Comparing and optimizing source detection procedures for XMM images. By constructing realistic spatial and spectral source distributions and ``observing'' these through the XMM Science…

Astrophysics · Physics 2007-05-23 Jesper Rasmussen , Kristian Pedersen , Martin Gotz

Watermarking language models is essential for distinguishing between human and machine-generated text and thus maintaining the integrity and trustworthiness of digital communication. We present a novel green/red list watermarking approach…

Machine Learning · Statistics 2025-06-13 Yangxinyu Xie , Xiang Li , Tanwi Mallick , Weijie J. Su , Ruixun Zhang

In CMB science, the simplest idea to remove a contaminated sky region is to multiply the sky map with a mask that is 0 for the contaminated region and 1 elsewhere, which is also called a top-hat masking. Although it is easy to use, such…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-15 Hao Liu , James Creswell , Sebastian von Hausegger , Pavel Naselsky

A large fraction of the previously estimated WMAP CMB quadrupole signal would be an artefact of incorrect Doppler dipole subtraction if the hypothesis of a small timing interpolation error were correct. Observations of bright foreground…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Boudewijn F. Roukema

In array processing, a common problem is to estimate the angles of arrival of $K$ deterministic sources impinging on an array of $M$ antennas, from $N$ observations of the source signal, corrupted by gaussian noise. The problem reduces to…

Probability · Mathematics 2011-06-28 Walid Hachem , Philippe Loubaton , Xavier Mestre , Jamal Najim , Pascal Vallet

We describe an X-ray source detection method entirely based on the maximum likelihood analysis, in application to observations with the ART-XC telescope onboard the Spectrum Roentgen Gamma observatory. The method optimally combines the data…

High Energy Astrophysical Phenomena · Physics 2024-04-03 A. Semena , A. Vikhlinin , I. Mereminskiy , A. Lutovinov , A. Tkachenko , I. Lapshov , R. Burenin

Multiply connected space sections of the universe on a scale smaller than the horizon size can leave an imprint on cosmic microwave background polarization maps, in such a way that the so-called ``circles-in-the-sky'' method can be used to…

In this work, we investigate the optimal map-making technique for the linear system $d=Ax+n$ while carefully taking into account singularities that may come from either the covariance matrix $C = \langle nn^t \rangle$ or the main matrix…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-09 Zirui Zhang , Yiwen Wu , Yang Liu , Siyu Li , Hong Li , Hao Liu

Upcoming surveys will measure the cosmic microwave background (CMB) weak lensing power spectrum in exquisite detail, allowing for strong constraints on the sum of neutrino masses among other cosmological parameters. Standard CMB lensing…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-23 Delon Shen , Emmanuel Schaan , Simone Ferraro

Machine learning (ML) approaches to data analysis are now widely adopted in many fields including epidemiology and medicine. To apply these approaches, confounds must first be removed as is commonly done by featurewise removal of their…

Optical measurements often exhibit mixed Poisson-Gaussian noise statistics, which hampers image quality, particularly under low signal-to-noise ratio (SNR) conditions. Computational imaging falls short in such situations when solely…

Image and Video Processing · Electrical Eng. & Systems 2023-11-16 Jacob Seifert , Yifeng Shao , Rens van Dam , Dorian Bouchet , Tristan van Leeuwen , Allard P. Mosk

Although interesting in themselves, extragalactic sources emitting in the microwave range (mainly radio-loud active galactic nuclei and dusty galaxies) are also considered a contaminant from the point of view of Cosmic Microwave Background…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 P. Diego-Palazuelos , P. Vielva , D. Herranz

In observation of the cosmic microwave background (CMB) polarization, "$EB$~leakage" refers to the artificial $B$-mode signal coming from the leakage of $E$-mode signal when part of the sky is unavailable or excluded. Correction of such…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-31 Hao Liu , James Creswell , Sebastian von Hausegger , Pavel Naselsky

We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements,…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-23 Alex Hall , Andy Taylor

Computational couplings of Markov chains provide a practical route to unbiased Monte Carlo estimation that can utilize parallel computation. However, these approaches depend crucially on chains meeting after a small number of transitions.…

Methodology · Statistics 2021-04-14 Brian L. Trippe , Tin D. Nguyen , Tamara Broderick

We revisit the problem of exact CMB likelihood and power spectrum estimation with the goal of minimizing computational cost through linear compression. This idea was originally proposed for CMB purposes by Tegmark et al.\ (1997), and here…

Instrumentation and Methods for Astrophysics · Physics 2015-11-18 E. Gjerløw , L. P. L. Colombo , H. K. Eriksen , K. M. Górski , A. Gruppuso , J. B. Jewell , S. Plaszczynski , I. K. Wehus

Inhomogeneous reionization gives rise to angular fluctuations in the Cosmic Microwave Background (CMB) optical depth tau(n) to the last scattering surface, correlating different spherical harmonic modes and imprinting characteristic…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-24 Meng Su , Amit P. S. Yadav , Matthew McQuinn , Jaiyul Yoo , Matias Zaldarriaga

Data separation is a well-studied phenomenon that can cause problems in the estimation and inference from binary response models. Complete or quasi-complete separation occurs when there is a combination of regressors in the model whose…

Methodology · Statistics 2021-01-19 Susanne Köll , Ioannis Kosmidis , Christian Kleiber , Achim Zeileis

In image processing, source detections are inevitably affected by the presence of the geometric boundaries in the images, including the physical boundaries of the CCD, and the boundaries of masked regions due to column defects, bright…

Instrumentation and Methods for Astrophysics · Physics 2021-04-21 Haoran Wang , Jun Zhang , Hekun Li , Zhi Shen