English
Related papers

Related papers: Exploring the likelihood of the 21-cm power spectr…

200 papers

The high-redshift 21-cm signal of neutral hydrogen is expected to be observed within the next decade and will reveal epochs of cosmic evolution that have been previously inaccessible. Due to the lack of observations, many of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-16 Aviad Cohen , Anastasia Fialkov , Rennan Barkana

Many statistical models in cosmology can be simulated forwards but have intractable likelihood functions. Likelihood-free inference methods allow us to perform Bayesian inference from these models using only forward simulations, free from…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-11 Justin Alsing , Benjamin Wandelt , Stephen Feeney

The growing availability of large and complex datasets has increased interest in temporal stochastic processes that can capture stylized facts such as marginal skewness, non-Gaussian tails, long memory, and even non-Markovian dynamics.…

Machine Learning · Statistics 2025-10-09 Dan Leonte , Raphaël Huser , Almut E. D. Veraart

The hyperfine structure absorption lines of neutral hydrogen in spectra of high-redshift radio sources, known collectively as the 21-cm forest, have been demonstrated as a sensitive probe to the small-scale structures governed by the dark…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Tian-Yang Sun , Yue Shao , Yichao Li , Yidong Xu , He Wang , Xin Zhang

We describe a simulation for the distribution of galaxies focusing on the atomic Hydrogen content. We aim to make predictions for surveys of galaxies using the redshifted 21 cm line emission. We take the expected distribution of HI masses,…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-18 Sauraj Bharti , J. S. Bagla

The detection of the 21-cm signal at $z\gtrsim6$ will reveal insights into the properties of the first galaxies responsible for driving reionisation. To extract this information, we perform parameter inference which requires embedding 3D…

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

Standard cosmological analysis, which relies on two-point statistics, fails to extract the full information of the data. This limits our ability to constrain with precision cosmological parameters. Thus, recent years have seen a paradigm…

The 21 cm signal arising from fluctuations in the neutral hydrogen field, and its cross-correlation with other tracers of cosmic density, are promising probes of the high-redshift Universe. In this study, we assess the potential of the 21…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-26 Barun Maity

The post-reionization ${\rm HI}$ 21-cm signal is an excellent candidate for precision cosmology, this however requires accurate modelling of the expected signal. Sarkar et al. (2016) have simulated the real space ${\rm HI}$ 21-cm signal,…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-25 Debanjan Sarkar , Somnath Bharadwaj

Current constraints on models of galaxy evolution rely on morphometric catalogs extracted from multi-band photometric surveys. However, these catalogs are altered by selection effects that are difficult to model, that correlate in non…

Instrumentation and Methods for Astrophysics · Physics 2017-09-06 Sébastien Carassou , Valérie de Lapparent , Emmanuel Bertin , Damien Le Borgne

Current ground-based cosmological surveys, such as the Dark Energy Survey (DES), are predicted to discover thousands of galaxy-scale strong lenses, while future surveys, such as the Vera Rubin Observatory Legacy Survey of Space and Time…

Instrumentation and Methods for Astrophysics · Physics 2022-11-14 Jason Poh , Ashwin Samudre , Aleksandra Ćiprijanović , Brian Nord , Gourav Khullar , Dimitrios Tanoglidis , Joshua A. Frieman

We present a cosmological analysis of the X-ray-selected galaxy cluster sample from the XXL survey, employing a simulation-based inference (SBI) framework to jointly constrain cosmological parameters and X-ray scaling relations through…

Cosmic Dawn (CD) and Epoch of Reionization (EoR) are epochs of the Universe which host invaluable information about the cosmology and astrophysics of X-ray heating and hydrogen reionization. Radio interferometric observations of the 21-cm…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-10 Anchal Saxena , Alex Cole , Simon Gazagnes , P. Daniel Meerburg , Christoph Weniger , Samuel J. Witte

We explore the possibility of retrieving cosmological information from 21-cm tomographic data at intermediate redshift. The first step in our approach consists of training an encoder, composed of several three dimensional convolutional…

Instrumentation and Methods for Astrophysics · Physics 2025-07-30 Sambatra Andrianomena

The non-Gaussisan spatial distribution of galaxies traces the large-scale structure of the Universe and therefore constitutes a prime observable to constrain cosmological parameters. We conduct Bayesian inference of the $\Lambda$CDM…

We investigate whether a Gaussian likelihood is sufficient to obtain accurate parameter constraints from a Euclid-like combined tomographic power spectrum analysis of weak lensing, galaxy clustering and their cross-correlation. Testing its…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-03 Robin E. Upham , Michael L. Brown , Lee Whittaker

We present Sequential Neural Variational Inference (SNVI), an approach to perform Bayesian inference in models with intractable likelihoods. SNVI combines likelihood-estimation (or likelihood-ratio-estimation) with variational inference to…

Machine Learning · Statistics 2022-10-20 Manuel Glöckler , Michael Deistler , Jakob H. Macke

The redshifted 21cm signal from the post-reionization epoch is highly non-Gaussian; thus, higher-order statistics, such as the bispectrum, are required to extract this non-Gaussian information. However, high-signal-to-noise ratio detection…

Understanding properties of the first sources in the Universe using the redshifted \HI ~21-cm signal is one of the major aims of present and upcoming low-frequency experiments. We investigate the possibility of imaging the redshifted 21-cm…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-15 Raghunath Ghara , T. Roy Choudhury , Kanan K. Datta , Samir Choudhuri

The 21-cm signal from neutral hydrogen is anticipated to reveal critical insights into the formation of early cosmic structures during the Cosmic Dawn and the subsequent Epoch of Reionization. However, the intrinsic faintness of the signal,…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-27 Yuchen Liu , Eloy de Lera Acedo , Peter Sims