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Gaussian processes (GPs) are non-parametric probabilistic regression models that are popular due to their flexibility, data efficiency, and well-calibrated uncertainty estimates. However, standard GP models assume homoskedastic Gaussian…

Machine Learning · Computer Science 2025-01-08 Sebastian Ament , Elizabeth Santorella , David Eriksson , Ben Letham , Maximilian Balandat , Eytan Bakshy

Our main aim is to test the non-variability of the radial velocity (RV) of a sample of 2351 standard stars used for wavelength calibration of the RVS instrument onboard Gaia. In this paper, we present the spectroscopic analysis of these…

Solar and Stellar Astrophysics · Physics 2022-09-28 A. Boulkaboul , Y. Damerdji , T. Morel , Y. Frémat , C. Soubiran , E. Gosset , T. E. Abdelatif

Gaussian processes (GPs) are a class of Kernel methods that have shown to be very useful in geoscience and remote sensing applications for parameter retrieval, model inversion, and emulation. They are widely used because they are simple,…

Machine Learning · Computer Science 2020-05-21 J. Emmanuel Johnson , Valero Laparra , Gustau Camps-Valls

In this study, we introduce a novel analytical Gaussian Process (GP) cosmography methodology, leveraging the differentiable properties of GPs to derive key cosmological quantities analytically. Our approach combines cosmic chronometer (CC)…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-19 Bikash R. Dinda

The distortions of absorption line profiles caused by photospheric brightness variations on the surfaces of cool, main-sequence stars can mimic or overwhelm radial velocity (RV) shifts due to the presence of exoplanets. The latest…

Earth observation (EO) by airborne and satellite remote sensing and in-situ observations play a fundamental role in monitoring our planet. In the last decade, machine learning and Gaussian processes (GPs) in particular has attained…

Machine Learning · Computer Science 2020-07-03 Gustau Camps-Valls , Dino Sejdinovic , Jakob Runge , Markus Reichstein

Pulsars are known to display short-term variability. Recently, examples of longer-term emission variability have emerged that are often correlated with changes in the rotational properties of the pulsar. To further illuminate this…

High Energy Astrophysical Phenomena · Physics 2016-01-27 P. R. Brook , A. Karastergiou , S. Johnston , M. Kerr , R. M. Shannon , S. J. Roberts

This paper proposes a statistical verification framework using Gaussian processes (GPs) for simulation-based verification of stochastic nonlinear systems with parametric uncertainties. Given a small number of stochastic simulations, the…

Systems and Control · Computer Science 2017-10-03 John F. Quindlen , Ufuk Topcu , Girish Chowdhary , Jonathan P. How

For solar-type stars, spots and their associated magnetic regions induce radial velocity perturbations through the Doppler rotation signal and the suppression of convective blueshift -- collectively known as rotation-modulation. We…

Spectrographs like HARPS can now reach a sub-m/s precision in radial-velocity (RV) (Pepe & Lovis 2008). At this level of accuracy, we start to be confronted with stellar noise produced by 3 different physical phenomena: oscillations,…

Earth and Planetary Astrophysics · Physics 2015-05-20 X. Dumusque , N. C. Santos , S. Udry , C. Lovis , X. Bonfils

Decoders built on Gaussian processes (GPs) are enticing due to the marginalisation over the non-linear function space. Such models (also known as GP-LVMs) are often expensive and notoriously difficult to train in practice, but can be scaled…

Machine Learning · Statistics 2022-11-28 Pablo Moreno-Muñoz , Cilie W Feldager , Søren Hauberg

Aims. We observed the $\tau$ Boo system with the HARPS-N spectrograph to test a new observational strategy aimed at jointly studying asteroseismology, the planetary orbit, and star-planet magnetic interaction. Methods. We collected…

This work addresses the issue of motion compensation and pattern tracking in event camera data. An event camera generates asynchronous streams of events triggered independently by each of the pixels upon changes in the observed intensity.…

Computer Vision and Pattern Recognition · Computer Science 2023-03-07 Cedric Le Gentil , Ignacio Alzugaray , Teresa Vidal-Calleja

Gaussian processes (GPs) are commonly used as a model of stochastic variability in astrophysical time series. In particular, GPs are frequently employed to account for correlated stellar variability in planetary transit light curves. The…

Instrumentation and Methods for Astrophysics · Physics 2020-11-11 Tyler Gordon , Eric Agol , Daniel Foreman-Mackey

Gaussian processes (GPs) provide a framework for Bayesian inference that can offer principled uncertainty estimates for a large range of problems. For example, if we consider regression problems with Gaussian likelihoods, a GP model enjoys…

Machine Learning · Computer Science 2022-12-21 Felix Leibfried , Vincent Dutordoir , ST John , Nicolas Durrande

We present a framework for transfer learning based on modular variational Gaussian processes (GP). We develop a module-based method that having a dictionary of well fitted GPs, one could build ensemble GP models without revisiting any data.…

Machine Learning · Statistics 2021-10-27 Pablo Moreno-Muñoz , Antonio Artés-Rodríguez , Mauricio A. Álvarez

Accurately modeling effects from stellar activity is a key step in detecting radial velocity signals of low-mass and long-period exoplanets. Radial velocities from stellar activity are dominated by magnetic active regions that move in and…

Earth and Planetary Astrophysics · Physics 2020-01-08 Chantanelle Nava , Mercedes López-Morales , Raphaëlle D. Haywood , Helen A. C. Giles

The doppler measurements of stars are diluted and distorted by stellar activity noise. Different choices of noise models and statistical methods have led to much controversy in the confirmation of exoplanet candidates obtained through…

Earth and Planetary Astrophysics · Physics 2016-07-27 Fabo Feng , M. Tuomi , H. R. A. Jones , R. P. Butler , S. Vogt

Earth observation from satellite sensory data poses challenging problems, where machine learning is currently a key player. In recent years, Gaussian Process (GP) regression has excelled in biophysical parameter estimation tasks from…

To date, only 18 exoplanets with radial velocity (RV) semi-amplitudes $<2$ m/s have had their masses directly constrained. The biggest obstacle to RV detection of such exoplanets is variability intrinsic to stars themselves, e.g. nuisance…