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Gaussian process regression (GPR) has been a well-known machine learning method for various applications such as uncertainty quantifications (UQ). However, GPR is inherently a data-driven method, which requires sufficiently large dataset.…

Machine Learning · Computer Science 2023-05-03 Cheng Chang , Tieyong Zeng

Gaussian processes (GPs) have gained popularity as flexible machine learning models for regression and function approximation with an in-built method for uncertainty quantification. However, GPs suffer when the amount of training data is…

Machine Learning · Statistics 2025-11-26 Jonas Latz , Aretha L. Teckentrup , Simon Urbainczyk

Foreground removal remains an ongoing challenge in radio cosmology, and increasingly sensitive experiments necessitate more robust analysis techniques. In this work, we model simulated data from a single-dish intensity mapping experiment,…

Instrumentation and Methods for Astrophysics · Physics 2026-04-30 Geoff G. Murphy , Philip Bull , Mario G. Santos , Zheng Zhang , Steven Cunnington

Edge transport barriers (ETBs) in magnetically confined fusion plasmas, commonly known as pedestals, play a crucial role in achieving high confinement plasmas. However, their defining characteristic, a steep rise in plasma pressure over…

We present a code that removes $\sim 90\%$ of the variance in astrometric measurements caused by atmospheric turbulence, by using Gaussian process regression (GPR) to interpolate the turbulence field from the positions of stars measured by…

Instrumentation and Methods for Astrophysics · Physics 2025-08-29 Daniel C. H. Gomes , Gary M. Bernstein , Claire-Alice Hébert

Cross-correlations between 21cm observations and galaxy surveys provide a powerful probe of reionization by reducing foreground sensitivity while linking ionization morphology to galaxies. We quantify the constraining power of 21cm-Galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-27 Yannic Pietschke , Anne Hutter , Caroline Heneka

Accurate channel state information (CSI) is critical for current and next-generation multi-antenna systems. Yet conventional pilot-based estimators incur prohibitive overhead as antenna counts grow. In this paper, we address this challenge…

Signal Processing · Electrical Eng. & Systems 2026-01-05 Syed Luqman Shah , Nurul Huda Mahmood , Italo Atzeni

The precise measurement of the sky-averaged HI absorption signal between 50 and 200 MHz is the primary goal of global 21-cm cosmology. This measurement has the potential to unravel the underlying physics of cosmic structure formation and…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-04 Emma Shen , Dominic Anstey , Marta Spinelli , Eloy de Lera Acedo , Anastasia Fialkov

[Abridged] The spatially averaged global spectrum of the redshifted 21cm line has generated much experimental interest, for it is potentially a direct probe of the Epoch of Reionization and the Dark Ages. Since the cosmological signal here…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-07 Adrian Liu , Jonathan R. Pritchard , Max Tegmark , Abraham Loeb

The 21 cm line of neutral hydrogen is a promising probe of the Epoch of Reionization (EoR) but suffers from contamination by spectrally smooth foregrounds, which obscure the large-scale signal along the line of sight. We explore the…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-26 Wenzer Qin , Kai-Feng Chen , Katelin Schutz , Adrian Liu

We investigate the implications of interference detection for experiments that are pursuing a detection of the redshifted 21-cm signals from the Epoch of Reionization. Interference detection causes samples to be sporadically flagged and…

Instrumentation and Methods for Astrophysics · Physics 2019-03-13 A. R. Offringa , F. Mertens , L. V. E. Koopmans

A radio interferometer indirectly measures the intensity distribution of the sky over the celestial sphere. Since measurements are made over an irregularly sampled Fourier plane, synthesising an intensity image from interferometric…

Instrumentation and Methods for Astrophysics · Physics 2014-03-18 Daniel Muscat

We propose a novel, Gaussian signaling mechanism for low probability of detection (LPD) communication systems with either single or multiple antennas. The new scheme is designed to allow the noncoherent detection of Gaussian-distributed…

Signal Processing · Electrical Eng. & Systems 2023-01-10 Yuma Katsuki , Giuseppe Thadeu Freitas de Abreu , Koji Ishibashi , Naoki Ishikawa

We study synergies between three promising methods to measure $2<z<5$ large-scale structure in the next decade. Optical spectroscopic surveys are the most mature, but become increasingly difficult at $z>2$ and suffer from interloper…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-24 Shi-Fan Chen , Emanuele Castorina , Martin White , Anže Slosar

Aiming to correctly restore the redshifted 21 cm signals emitted by the neutral hydrogen during the cosmic reionization processes, we re-examine the separation approaches based on the quadratic polynomial fitting technique in frequency…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Jingying Wang , Haiguang Xu , Tao An , Junhua Gu , Xueying Guo , Weitian Li , Yu Wang , Chengze Liu , Olivier Martineau-Huynh , Xiang-Ping Wu

Foreground removal presents a significant obstacle in both current and forthcoming intensity mapping surveys. While numerous techniques have been developed that show promise in simulated datasets, their efficacy often diminishes when…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-14 Jiacheng Ding , Xin Wang , Ue-Li Pen , Xiao-Dong Li

We explore the properties of interferometric data from high-redshift 21~cm measurements using the Murchison Widefield Array. These data contain redshifted 21~cm signal, contamination from continuum foreground sources, and radiometric noise.…

We study the detectability of the cross-correlation between 21 cm emission from the intergalactic medium and the galaxy distribution during (and before) reionization. We show that first-generation 21 cm experiments, such as the Mileura…

Astrophysics · Physics 2009-11-11 Steven Furlanetto , Adam Lidz

Future gravitational wave (GW) standard siren catalogues will probe the late-time expansion history of the Universe across redshift ranges largely inaccessible to traditional electromagnetic observations. To determine how effectively this…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-27 Gourab Nandi , Anish Ghoshal , David F. Mota