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The future of precision cosmology could benefit from cross-correlations between intensity maps of unresolved neutral hydrogen (HI) and more conventional optical galaxy surveys. A major challenge that needs to be overcome is removing the…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-17 Steven Cunnington , Laura Wolz , Alkistis Pourtsidou , David Bacon

We develop a fast variational approximation scheme for Gaussian process (GP) regression, where the spectrum of the covariance function is subjected to a sparse approximation. Our approach enables uncertainty in covariance function…

Computation · Statistics 2019-04-24 Linda S. L. Tan , Victor M. H. Ong , David J. Nott , Ajay Jasra

The 21cm forest, narrow absorption features in the spectra of high redshift radio sources caused by intervening neutral hydrogen, offers a unique probe of the intergalactic medium and small-scale structures during reionization. While…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-30 Hayato Shimabukuro , Yidong Xu , Yue Shao

The cosmic 21-cm signal is a promising probe of the early Universe, owing to its sensitivity to the thermal state of the neutral intergalactic medium (IGM) and properties of the first luminous sources. Here, we constrain the 21-cm signal…

The 21-cm brightness temperature fluctuation from the Dark Ages ($z \simeq 30-100$) will allow us to probe the inflationary epoch on very small scales ($>0.1 \, \mbox{Mpc}^{-1}$), inaccessible to cosmic microwave background experiments.…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-28 Giorgio Orlando , Thomas Flöss , P. Daniel Meerburg , Joseph Silk

As the hunt for an Earth-like exoplanets has intensified in recent years, so has the effort to characterise and model the stellar signals that can hide or mimic small planetary signals. Stellar variability arises from a number of sources,…

Solar and Stellar Astrophysics · Physics 2024-04-19 Niamh K. O'Sullivan , Suzanne Aigrain

Gaussian process regression (GPR) is a popular nonparametric Bayesian method that provides predictive uncertainty estimates and is widely used in safety-critical applications. While prior research has introduced various uncertainty bounds,…

Machine Learning · Computer Science 2025-12-05 Junyi Liu , Stanley Kok

Satellite-based positioning system such as GPS often suffers from large amount of noise that degrades the positioning accuracy dramatically especially in real-time applications. In this work, we consider a data-mining approach to enhance…

Machine Learning · Statistics 2019-06-05 Ming Lin , Xiaomin Song , Qi Qian , Hao Li , Liang Sun , Shenghuo Zhu , Rong Jin

Several models of gamma-ray burst progenitors suggest that the gamma-ray event may be followed by gravitational wave signals of $10^3$-$10^4$ seconds duration (possibly accompanying the so-called X-ray afterglow "plateaus"). We term these…

General Relativity and Quantum Cosmology · Physics 2016-08-24 Robert Coyne , Alessandra Corsi , Benjamin J. Owen

21cm radiation from neutral hydrogen serves as a direct probe of the Epoch of Reionization. However, both its detection and physical interpretation are severely hindered by contamination from astrophysical foreground emission and…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-07 Anirban Chakraborty , Kwanit Gangopadhyay , Arka Banerjee , Tirthankar Roy Choudhury

The redshifted 21 cm line of neutral hydrogen is a promising probe of the Epoch of Reionization (EoR). However, its detection requires a thorough understanding and control of the systematic errors. We study two systematic biases observed in…

The \hi 21 cm transition line is expected to be an important probe into the cosmic dark ages and epoch of reionization. Foreground source removal is one of the principal challenges for the detection of this signal. This paper investigates…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 A. Datta , J. D. Bowman , C. L. Carilli

Mechanistic simulation models are inverted against observations in order to gain inference on modeled processes. However, with the increasing ability to collect high resolution observations, these observations represent more patterns of…

Computation · Statistics 2018-12-20 Thomas Wutzler

We present a method for coherently combining short data segments from gravitational-wave detectors to improve the sensitivity of semi-coherent searches for continuous gravitational waves. All-sky searches for continuous gravitational waves…

General Relativity and Quantum Cosmology · Physics 2016-04-13 Evan Goetz , Keith Riles

We examine the properties of an excess power method to detect gravitational waves in interferometric detector data. This method is designed to detect short-duration (< 0.5 s) burst signals of unknown waveform, such as those from supernovae…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Warren G. Anderson , Patrick R. Brady , Jolien D. E. Creighton , Eanna E. Flanagan

This paper proposes a hybrid Gaussian process (GP) approach to robust economic model predictive control under unknown future disturbances in order to reduce the conservatism of the controller. The proposed hybrid GP is a combination of two…

Systems and Control · Electrical Eng. & Systems 2020-01-08 Mohammadreza Rostam , Ryozo Nagamune , Vladimir Grebenyuk

Non-conventional receivers for phase-coherent states based on non-Gaussian measurements such as photon counting surpass the sensitivity limits of shot-noise-limited coherent receivers, the quantum noise limit (QNL). These non-Gaussian…

Quantum Physics · Physics 2020-07-07 M. T. DiMario , F. E. Becerra

We investigate the cross-correlation between the spatial distribution of Lyman Break Galaxies (LBGs) and the 21cm intensity mapping signal at $z\sim[3-5]$. At these redshifts, galactic feedback is supposed to only marginally affect the…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-09 Francisco Villaescusa-Navarro , Matteo Viel , David Alonso , Kanan K. Datta , Philip Bull , Mario G. Santos

Enlightening our understanding of the first galaxies responsible for driving reionisation requires detecting the 21-cm signal from neutral hydrogen. Interpreting the wealth of information embedded in this signal requires Bayesian inference.…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-22 Bradley Greig , David Prelogović , Yuxiang Qin , Yuan-Sen Ting , Andrei Mesinger

Many low-frequency radio interferometers are aiming to detect very faint spectral signatures from structures at cosmological redshifts, particularly of neutral Hydrogen using its characteristic 21 cm spectral line. Due to the very high…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-03 Nithyanandan Thyagarajan , Chris Carilli