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Many Bayesian statistical inference problems come down to computing a maximum a-posteriori (MAP) assignment of latent variables. Yet, standard methods for estimating the MAP assignment do not have a finite time guarantee that the algorithm…

Machine Learning · Statistics 2024-10-31 Harsh Vardhan Dubey , Ji Ah Lee , Patrick Flaherty

Line-of-sight distortions of the cosmic microwave background (CMB), including gravitational lensing, cosmic birefringence, and patchy screening, encode crucial cosmological information. While quadratic estimators (QE) have been excellent…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-06 Omar Darwish

A new method for estimating the angular power spectrum C_l from cosmic microwave background (CMB) maps is presented, which has the following desirable properties: (1) It is unbeatable in the sense that no other method can measure C_l with…

Astrophysics · Physics 2009-10-07 Max Tegmark

Simulated observations of a $10\dg \times 10\dg$ field by the Microwave Anisotropy Probe (MAP) are analysed in order to separate cosmic microwave background (CMB) emission from foreground contaminants and instrumental noise and thereby…

Astrophysics · Physics 2009-10-31 A. W. Jones , M. P. Hobson , A. N. Lasenby

The statistical analysis of the soon to come Planck satellite CMB data will help set tighter bounds on major cosmological parameters. On the way, a number of practical difficulties need to be tackled, notably that several other…

Astrophysics · Physics 2009-11-13 P. Abrial , Y. Moudden , J. -L. Starck , J. Fadili , J. Delabrouille , M. K. Nguyen

(Abridged) We present a new method for detecting and measuring compact sources in conditions of intense, and highly variable, fore/background. While all most commonly used packages carry out the source detection over the signal image, our…

One of the main obstacles for extracting the Cosmic Microwave Background (CMB) from mm/submm observations is the pollution from the main Galactic components: synchrotron, free-free and thermal dust emission. The feasibility of using simple…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-20 H. U. Nørgaard-Nielsen

In this contribution, we present new algorithms to source separation for the case of noisy instantaneous linear mixture, within the Bayesian statistical framework. The source distribution prior is modeled by a mixture of Gaussians…

Data Analysis, Statistics and Probability · Physics 2009-11-07 Hichem Snoussi , Ali Mohammad-Djafari

Observations of Cosmic Microwave Background (CMB) B-mode polarization provide a way to probe primordial gravitational waves and test inflationary predictions. Extragalactic point sources become a major source of contamination after…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-16 Yi-Ming Wang , Wen-Zheng Chen , Yang Liu , Si-Yu Li , Hong Li

The light we receive from distant astrophysical objects carries information about their origins and the physical mechanisms that power them. The study of these signals, however, is complicated by the fact that observations are often a…

Accurate measurements of the Cosmic Microwave Background (CMB) anisotropy call for high precision and reliability of the in-flight calibration. For extended surveys the CMB dipole provides an excellent calibration source at frequencies…

Astrophysics · Physics 2009-11-10 B. Cappellini , D. Maino , G. Albetti , P. Platania , R. Paladini , A. Mennella , M. Bersanelli

We present a randomized maximum a posteriori (rMAP) method for generating approximate samples of posteriors in high dimensional Bayesian inverse problems governed by large-scale forward problems. We derive the rMAP approach by: 1) casting…

Computation · Statistics 2016-02-12 Kainan Wang , Tan Bui-Thanh , Omar Ghattas

We investigate the extent to which foreground cleaned CMB maps can be used to estimate the cosmological parameters at small scales. We use the SMICA method, a blind separation technique which works directly at the spectral level. In this…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-17 C. Umiltà , J. F. Cardoso , K. Benabed , M. Le Jeune

We present a comprehensive neural architecture, the PUREPath, which leverages a nested Probabilistic multi-modal U- Net framework, augmented by the inclusion of probabilistic ResNet blocks in the Expanding Pathway of the decoders, to…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-01 Vipin Sudevan , Pisin Chen

We describe a new map-making code for cosmic microwave background (CMB) observations. It implements fast algorithms for convolution and transpose convolution of two functions on the sphere (Wandelt & G\'{o}rski 2001). Our code can account…

Astrophysics · Physics 2009-11-10 Charmaine Armitage , Benjamin D. Wandelt

CMB data analysis is in general done through two main steps : map-making of the time data streams and power spectrum extraction from the maps. The latter basically consists in the separation between the variance of the CMB and that of the…

Astrophysics · Physics 2007-05-23 J. -Ch. Hamilton

We show how one may expect a significant number of SZ detections in future Planck data without any of the typical assumptions needed in present component separation methods, such as about the power spectrum or the frequency dependence of…

Astrophysics · Physics 2009-11-07 J. M. Diego , P. Vielva , E. Martinez-Gonzalez , J. Silk , J. L. Sanz

Mitigation of the impact of foreground contributions to measurements of Cosmic Microwave Background (CMB) polarization is a crucial step in modern CMB data analysis and is of particular importance for a detection of large-scale CMB $B$…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-14 Clément Leloup , Josquin Errard , Radek Stompor

We present a new method for analyzing multi--detector maps containing contributions from several components. Our method, based on matching the data to a model in the spectral domain, permits to estimate jointly the spatial power spectra of…

Astrophysics · Physics 2009-11-07 J. Delabrouille , J. -F. Cardoso , G. Patanchon

We apply a Cross-correlation (CC) method developed previously for detecting gamma-ray point sources to the WMAP first year data by using the Point-Spread Function of WMAP and obtain a full sky CC coefficient map. Analyzing this map, we find…

Astrophysics · Physics 2009-11-11 Jian Yin Nie , Shuang Nan Zhang