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A functional approximation to implement Bayesian source separation analysis is introduced and applied to separation of the Cosmic Microwave Background (CMB) using WMAP data. The approximation allows for tractable full-sky map…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Simon P. Wilson , Jiwon Yoon

We introduce a methodology for robust Bayesian estimation with robust divergence (e.g., density power divergence or {\gamma}-divergence), indexed by a single tuning parameter. It is well known that the posterior density induced by robust…

Methodology · Statistics 2022-07-04 Shouto Yonekura , Shonosuke Sugasawa

In 21cm intensity mapping of the large-scale structure (LSS), regions in Fourier space could be compromised by foreground contamination. In interferometric observations, this contamination, known as the foreground wedge, is exacerbated by…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-27 Qian Li , Xin Wang , Xiaodong Li , Jiacheng Ding , Tiancheng Luan , Xiaolin Luo

A detailed map of the distribution of dust at high Galactic latitudes is essential for future cosmic microwave background (CMB) polarization experiments because the dust, while diffuse, remains a significant foreground in these regions. We…

Astrophysics of Galaxies · Physics 2024-10-16 Matthew O'Callaghan , Gerry Gilmore , Kaisey S. Mandel

We present two estimators to quantify the angular power spectrum of the sky signal directly from the visibilities measured in radio interferometric observations. This is relevant for both the foregrounds and the cosmological 21-cm signal…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-11 Samir Choudhuri , Somnath Bharadwaj , Abhik Ghosh , SK. Saiyad Ali

The extraction of foreground and CMB maps from multi-frequency observations relies mostly on the different frequency behavior of the different components. Existing Bayesian methods additionally make use of a Gaussian prior for the CMB whose…

Instrumentation and Methods for Astrophysics · Physics 2014-07-04 Niels Oppermann , Torsten A. Enßlin

We investigate the problem of recovering a structured sparse signal from a linear observation model with an uncertain dynamic grid in the sensing matrix. The state-of-the-art expectation maximization based compressed sensing (EM-CS)…

Signal Processing · Electrical Eng. & Systems 2024-07-25 An Liu , Yufan Zhou , Wenkang Xu

The observation of the polarised emission from the Cosmic Microwave Background (CMB) from future ground-based and satellite-borne experiments holds the promise of indirectly detecting the elusive signal from primordial tensor fluctuations…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-22 Susanna Azzoni , David Alonso , Maximilian H. Abitbol , Josquin Errard , Nicoletta Krachmalnicoff

Sparse regression based on global-local shrinkage priors are increasingly used for Bayesian modeling of modern high-dimensional data, but scaling up the Gibbs sampler for posterior inference remains a challenge. While much effort has gone…

Methodology · Statistics 2026-05-08 Andrew Chin , Xiyu Ding , Akihiko Nishimura

We present an implementation of a blind source separation algorithm to remove foregrounds off millimeter surveys made by single-channel instruments. In order to make possible such a decomposition over single-wavelength data: we generate…

Radio interferometric experiments aim to constrain the reionization model parameters by measuring the 21-cm signal statistics, primarily the power spectrum. However the Epoch of Reionization (EoR) 21-cm signal is highly non-Gaussian, and…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-04 Himanshu Tiwari , Abinash Kumar Shaw , Suman Majumdar , Mohd Kamran , Madhurima Choudhury

We propose the HI 21-cm power spectrum from the post-reionization epoch as a probe of a cosmological model with decaying dark matter particles. The unstable particles are assumed to undergo a 2-body decay into a massless and massive…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-12 Mohit Yadav , Tapomoy Guha Sarkar

The precise characterization and mitigation of systematic effects is one of the biggest roadblocks impeding the detection of the fluctuations of cosmological 21cm signals. Missing data in radio cosmological experiments, often due to radio…

In light of the ever-increasing demand for new spectral bands and the underutilization of those already allocated, the concept of Cognitive Radio (CR) has emerged. Opportunistic users could exploit temporarily vacant bands after detecting…

Information Theory · Computer Science 2015-06-17 Deborah Cohen , Yonina C. Eldar

The focus in this paper is Bayesian system identification based on noisy incomplete modal data where we can impose spatially-sparse stiffness changes when updating a structural model. To this end, based on a similar hierarchical sparse…

Applications · Statistics 2017-02-07 Yong Huang , James L. Beck , Hui Li

We study the sparse high-dimensional Gaussian mixture model when the number of clusters is allowed to grow with the sample size. A minimax lower bound for parameter estimation is established, and we show that a constrained maximum…

Statistics Theory · Mathematics 2024-02-26 Dapeng Yao , Fangzheng Xie , Yanxun Xu

This paper addresses the problem of separating spectral sources which are linearly mixed with unknown proportions. The main difficulty of the problem is to ensure the full additivity (sum-to-one) of the mixing coefficients and…

Methodology · Statistics 2010-08-30 Nicolas Dobigeon , Said Moussaoui , Jean-Yves Tourneret , Cedric Carteret

All-sky observations of the Milky Way show both Galactic and non-Galactic diffuse emission, for example from interstellar matter or the cosmic microwave background (CMB). The different emitters are partly superimposed in the measurements,…

Instrumentation and Methods for Astrophysics · Physics 2021-06-16 Sara Milosevic , Philipp Frank , Reimar H. Leike , Ancla Müller , Torsten A. Enßlin
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