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Performing exact posterior inference in complex generative models is often difficult or impossible due to an expensive to evaluate or intractable likelihood function. Approximate Bayesian computation (ABC) is an inference framework that…

Machine Learning · Statistics 2016-02-16 Jovana Mitrovic , Dino Sejdinovic , Yee Whye Teh

We use the very deep XMM-Newton observations in the CDF-S to measure the distribution of absorption in the AGN population. We describe the Monte Carlo method used to unveil the intrinsic properties of the AGN using their multi-band X-ray…

Astrophysics · Physics 2007-05-23 Tom Dwelly , Mathew J. Page

We present a new Bayesian methodology to learn the unknown material density of a given sample by inverting its two-dimensional images that are taken with a Scanning Electron Microscope. An image results from a sequence of projections of the…

Applications · Statistics 2014-03-06 Dalia Chakrabarty , Fabio Rigat , Nare Gabrielyan , Richard Beanland , Shashi Paul

We consider Bayesian inference problems with computationally intensive likelihood functions. We propose a Gaussian process (GP) based method to approximate the joint distribution of the unknown parameters and the data. In particular, we…

Computation · Statistics 2018-03-15 Hongqiao Wang , Jinglai Li

Since its launch in 1999, the XMM-\textit{Newton} mission has compiled the largest catalogue of serendipitous X-ray sources, with the 3XMM being the third version of this catalogue. This is because of the combination of a large effective…

Astrophysics of Galaxies · Physics 2022-02-02 A. Ruiz , I. Georgantopoulos , A. Corral

Bayesian Generative AI (BayesGen-AI) methods are developed and applied to Bayesian computation. BayesGen-AI reconstructs the posterior distribution by directly modeling the parameter of interest as a mapping (a.k.a. deep learner) from a…

Computation · Statistics 2024-02-27 Nicholas G. Polson , Vadim Sokolov

In the present study, we use the DES Y3 catalog of LRG to incorporate the realistic galaxies' redshift Probability Distribution Function(PDF) into the correlation function cosmological model. We used four different photo-z estimators ANNz2,…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-06 Paula S. Ferreira , Ribamar R. R. Reis

The XMM-LSS, XMM-COSMOS, and XMM-CDFS surveys are complementary in terms of sky coverage and depth. Together, they form a clean sample with the least possible variance in instrument effective areas and PSF. Therefore this is one of the best…

Context: Redshifts are fundamental for our understanding of extragalactic X-ray sources. Ambiguous counterpart associations, expensive optical spectroscopy and/or multimission multiwavelength coverage to resolve degeneracies make estimation…

Instrumentation and Methods for Astrophysics · Physics 2018-10-17 Charlotte Simmonds , Johannes Buchner , Mara Salvato , Li-Ting Hsu , Franz Erik Bauer

We apply machine learning in the form of a nearest neighbor instance-based algorithm (NN) to generate full photometric redshift probability density functions (PDFs) for objects in the Fifth Data Release of the Sloan Digital Sky Survey (SDSS…

X-ray spectroscopy offers an opportunity to study the complex mixture of emitting and absorbing components in the circumnuclear regions of active galactic nuclei, and to learn about the accretion process that fuels AGN and the feedback of…

High Energy Astrophysical Phenomena · Physics 2009-11-13 T. J. Turner , L. Miller

In high-dimensional Bayesian statistics, various methods have been developed, including prior distributions that induce parameter sparsity to handle many parameters. Yet, these approaches often overlook the rich spectral structure of the…

Statistics Theory · Mathematics 2025-05-06 Tomoya Wakayama , Masaaki Imaizumi

X-ray extragalactic surveys are ideal laboratories for the study of the evolution and clustering of active galactic nuclei (AGN). The XXL Survey spans two fields of a combined 50 $deg^2$ observed for more than 6Ms with XMM-Newton, occupying…

Until recently, the use of Bayesian inference in population genetics was limited to a few cases because for many realistic population genetic models the likelihood function cannot be calculated analytically . The situation changed with the…

Methodology · Statistics 2009-01-16 Christoph Leuenberger Daniel Wegmann Laurent Excoffier

AGN are known to have complex X-ray spectra that depend on both the properties of the accreting SMBH (e.g. mass, accretion rate) and the distribution of obscuring material in its vicinity ("torus"). Often however, simple and even unphysical…

High Energy Astrophysical Phenomena · Physics 2014-05-08 J. Buchner , A. Georgakakis , K. Nandra , L. Hsu , C. Rangel , M. Brightman , A. Merloni , M. Salvato , J. Donley , D. Kocevski

We present a detailed and self-consistent modeling of the cosmic X-ray background (XRB) based on the most up-to-date X-ray luminosity functions (XLF) and evolution of Active Galactic Nuclei (AGN). The large body of observational results…

Astrophysics · Physics 2009-11-11 Roberto Gilli , Andrea Comastri , Guenther Hasinger

Methods based on Deep Learning have recently been applied on astrophysical parameter recovery thanks to their ability to capture information from complex data. One of these methods is the approximate Bayesian Neural Networks (BNNs) which…

Instrumentation and Methods for Astrophysics · Physics 2023-06-21 Héctor J. Hortúa , Luz Ángela García , Leonardo Castañeda C

In this paper we describe and publicly release a catalogue consisting of 8445 point-like X-ray sources detected in the XMM-XXL north survey. For the 2512 AGN which have reliable spectroscopy, we present the X-ray spectral fitting which has…

Global data association is an essential prerequisite for robot operation in environments seen at different times or by different robots. Repetitive or symmetric data creates significant challenges for existing methods, which typically rely…

Robotics · Computer Science 2025-09-22 Yixuan Jia , Mason B. Peterson , Qingyuan Li , Yulun Tian , Jonathan P. How

We formulate natural gradient variational inference (VI), expectation propagation (EP), and posterior linearisation (PL) as extensions of Newton's method for optimising the parameters of a Bayesian posterior distribution. This viewpoint…

Machine Learning · Statistics 2022-12-07 William J. Wilkinson , Simo Särkkä , Arno Solin