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We apply state-of-the art data analysis methods to a number of fictitious CMB mapping experiments, including 1/f noise, distilling the cosmological information from time-ordered data to maps to power spectrum estimates, and find that in all…

Astrophysics · Physics 2008-11-26 Max Tegmark

A new method for removing point radio sources and other non-Gaussian noise is proposed as a means of improving the accuracy of estimates of the angular power spectrum of the cosmic microwave background (CMB). The main idea of the method is…

Astrophysics · Physics 2009-11-13 Anisa T. Bajkova

Several researchers have proposed minimisation of maximum mean discrepancy (MMD) as a method to quantise probability measures, i.e., to approximate a target distribution by a representative point set. We consider sequential algorithms that…

Machine Learning · Statistics 2021-02-15 Onur Teymur , Jackson Gorham , Marina Riabiz , Chris. J. Oates

We present efficient algorithms for CMB lensing simulation and power spectrum es- timation for flat-sky CMB polarization maps. We build a pure B-mode estimator to remedy E to B leakage due to partial sky coverage. We show that our…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-14 Thibaut Louis , Sigurd Næss , Sudeep Das , Joanna Dunkley , Blake Sherwin

Spatial intensity moments computed on images can be used as a probe of the centroid, size, and orientation of pixelized sources such as stars and galaxies. However, all measurements made on images suffer from errors due to undersampling and…

Instrumentation and Methods for Astrophysics · Physics 2020-12-11 Andrew K. Bradshaw

MADmap is a software application used to produce maximum-likelihood images of the sky from time-ordered data which include correlated noise, such as those gathered by Cosmic Microwave Background (CMB) experiments. It works efficiently on…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 C. M. Cantalupo , J. D. Borrill , A. H. Jaffe , T. S. Kisner , R. Stompor

Flux estimates for faint sources or transients are systematically biased high because there are far more truly faint sources than bright. Corrections which account for this effect are presented as a function of signal-to-noise ratio and the…

Astrophysics · Physics 2009-10-30 David W. Hogg , Edwin L. Turner

E to B mixing or "leakage" due to time-ordered data (TOD) filtering has become an important source of sensitivity loss that ground-based cosmic microwave background polarization experiments must address. However, it is a difficult problem…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-20 Yuyang Zhou , Adrian Lee , Yuji Chinone

Obscuration due to Galactic emission complicates the extraction of information from cosmological surveys, and requires some combination of the (typically imperfect) modeling and subtraction of foregrounds, or the removal of part of the sky.…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-14 Stephen M. Feeney , Hiranya V. Peiris , Andrew Pontzen

This work describes Cosmic Microwave Background (CMB) data analysis algorithms and their implementations, developed to produce a pixelized map of the sky and a corresponding pixel-pixel noise correlation matrix from time ordered data for a…

Strong foreground contamination in high resolution CMB data requires masking which introduces statistical anisotropies and renders a full maximum likelihood analysis numerically intractable. Standard analysis methods like the pseudo-C_l…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-26 H. F. Gruetjen , E. P. S. Shellard

Pathloss is typically modeled using a log-distance power law with a large-scale fading term that is log-normal. However, the received signal is affected by the dynamic range and noise floor of the measurement system used to sound the…

Information Theory · Computer Science 2016-09-14 Carl Gustafson , Taimoor Abbas , David Bolin , Fredrik Tufvesson

Precision measurements of cosmic microwave background (CMB) polarization require extreme control of instrumental systematics. In a companion paper we have presented cosmological constraints from observations with the BICEP2 and Keck Array…

Code secrets are sensitive assets for software developers, and their leakage poses significant cybersecurity risks. While the rapid development of AI code assistants powered by Code Large Language Models (CLLMs), CLLMs are shown to…

Cryptography and Security · Computer Science 2026-04-21 Meifang Chen , Zhe Yang , Huang Nianchen , Yizhan Huang , Yichen Li , Zihan Li , Michael R. Lyu

Residual error in calibration coefficients corresponding to observed CMB maps is an important issue while estimating a pure CMB signal. A component separation method, if these errors in the input foreground contaminated CMB maps are not…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-21 Vipin Sudevan , Rajib Saha

CMB polarization signal may be decomposed into gradient-like (E) and curl-like (B) mode. We have investigated E/B decomposition in pixel space. We find E/B mixing due to incomplete sky is localized in pixel-space, and negligible in the…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-22 Jaiseung Kim , Pavel Naselsky

Procedures based on current methods to detect sources in X-ray images are applied to simulated XMM images. All significant instrumental effects are taken into account, and two kinds of sources are considered -- unresolved sources…

Astrophysics · Physics 2009-11-06 I. Valtchanov , M. Pierre , R. Gastaud

We present X-sifter, a software package designed for near-optimal detection of sources in X-ray images and other forms of photon images in the Poisson-noise regime. The code is based on the Poisson-noise-matched filter (Ofek & Zackay),…

Instrumentation and Methods for Astrophysics · Physics 2024-12-12 Maayane T. Soumagnac , Eran O. Ofek , Shachar S. Israeli , Guy Nir , Imri A. Dickstein

Maximum-likelihood exponent maps have been studied as a technique to increase the understanding and improve the fit of power-law exponents to experimental and numerical simulation data, especially when they exhibit both upper and lower…

Statistical Mechanics · Physics 2012-07-02 Jordi Baró , Eduard Vives

With the temperature power spectrum of the cosmic microwave background (CMB) at least four orders of magnitude larger than the B-mode polarisation power spectrum, any instrumental imperfections that couple temperature to polarisation must…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-22 Christopher G. R. Wallis , A. Bonaldi , Michael L. Brown , Richard A. Battye