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We explore linear and non-linear dimensionality reduction techniques for statistical inference of parameters in cosmology. Given the importance of compressing the increasingly complex data vectors used in cosmology, we address questions…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-12 Minsu Park , Marco Gatti , Bhuvnesh Jain

Cosmic Microwave Background temperature and polarization anisotropies from Planck have estimated a lower value of the optical depth to reionization ($\tau$) compared to WMAP. A significant period in the reionization history would then fall…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-19 Dhiraj Kumar Hazra , Daniela Paoletti , Fabio Finelli , George F. Smoot

Cosmic structure simulations have improved enormously over the past decade, both in terms of the resolution which can be achieved, and with the addition of hydrodynamic and other techniques to formerly purely gravitational methods. This is…

Astrophysics · Physics 2007-05-23 H. M. P. Couchman

In studies of the interstellar medium in galaxies, radiative transfer models of molecular emission are useful for relating molecular line observations back to the physical conditions of the gas they trace. However, doing this requires…

Astrophysics of Galaxies · Physics 2019-10-02 Damien de Mijolla , Serena Viti , Jonathan Holdship , Ioanna Manolopoulou , Jeremy Yates

Details of how the primordial plasma recombined and how the universe later reionized are currently somewhat uncertain. This uncertainty can restrict the accuracy of cosmological parameter measurements from the Cosmic Microwave Background…

Astrophysics · Physics 2008-11-26 Antony Lewis , Jochen Weller , Richard Battye

Numerical methods for radiative transfer play a key role in modern-day astrophysics and cosmology, including study of the inhomogeneous reionization process. In this context, ray tracing methods are well-regarded for accuracy but notorious…

Instrumentation and Methods for Astrophysics · Physics 2025-12-16 Nathan X. Marshak , Kathlynn Simotas , Zarija Lukić , Hyunbae Park , James Ahrens , Chris R. Johnson

The computational expense of solving non-equilibrium chemistry equations in astrophysical simulations poses a significant challenge, particularly in high-resolution, large-scale cosmological models. In this work, we explore the potential of…

Instrumentation and Methods for Astrophysics · Physics 2025-07-18 Pelle van de Bor , John Brennan , John A. Regan , Jonathan Mackey

We highlight recent progress in the sophistication and diversification of cosmic dawn and reionization simulations. The application of these modeling tools to current observations has allowed us narrow down the timing of reionization, which…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-22 Andrei Mesinger

This paper presents a unique approach to the problem of calculating revisit time metrics for different satellite orbits, sensor geometries, and constellation configurations with application to early lifecycle design and optimisation…

Computational Engineering, Finance, and Science · Computer Science 2018-07-06 Nicholas H. Crisp , Sabrina Livadiotti , Peter C. E. Roberts

Recent observations indicate that star formation occurs only in the molecular phase of a galaxy's interstellar medium. A realistic treatment of star formation in simulations and analytic models of galaxies therefore requires that one…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Mark R. Krumholz , Nickolay Y. Gnedin

High-redshift 21-cm observations will provide crucial insights into the physical processes of the Epoch of Reionization. Next-generation interferometers such as the Square Kilometer Array will have enough sensitivity to directly image the…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-27 Simon Gazagnes , Léon V. E. Koopmans , Michael H. F. Wilkinson

Traditional large-scale models of reionization usually employ simple deterministic relations between halo mass and luminosity to predict how reionization proceeds. We here examine the impact on modelling reionization of using more detailed…

Enhanced sampling algorithms have emerged as powerful methods to extend the utility of molecular dynamics simulations and allow the sampling of larger portions of the configuration space of complex systems in a given amount of simulation…

Statistical Mechanics · Physics 2022-12-19 Jérôme Hénin , Tony Lelièvre , Michael R. Shirts , Omar Valsson , Lucie Delemotte

This review article focuses on regularised estimation procedures applicable to geostatistical and spatial econometric models. These methods are particularly relevant in the case of big geospatial data for dimensionality reduction or model…

Methodology · Statistics 2026-04-30 Philipp Otto , Alessandro Fassò , Paolo Maranzano

We address the problem of belief change in (nonmonotonic) logic programming under answer set semantics. Unlike previous approaches to belief change in logic programming, our formal techniques are analogous to those of distance-based belief…

Artificial Intelligence · Computer Science 2009-12-31 James Delgrande , Torsten Schaub , Hans Tompits , Stefan Woltran

Atomistic simulations have become a powerful tool in materials research due to the extremely fine spatial and temporal resolution provided by such techniques. In order to understand the fundamental principles which govern material behavior…

Materials Science · Physics 2014-08-26 Jason F. Panzarino , Timothy J. Rupert

In recent years there has been considerable progress in our understanding of the nature and properties of the reionization process. In particular, the numerical simulations of this epoch have made a qualitative leap forward, reaching…

Upcoming large galaxy surveys will subject the standard cosmological model, $\Lambda$CDM, to new precision tests. These can be tightened considerably if theoretical models of galaxy formation are available that can predict galaxy clustering…

Topic modeling is a popular method used to describe biological count data. With topic models, the user must specify the number of topics $K$. Since there is no definitive way to choose $K$ and since a true value might not exist, we develop…

Applications · Statistics 2022-03-10 Julia Fukuyama , Kris Sankaran , Laura Symul

Impacts of observational systematic errors on the lensing analysis of the cosmic microwave background (CMB) polarization are investigated by numerical simulations. We model errors of gain, angle, and pointing in observation of the CMB…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-10 Ryo Nagata , Toshiya Namikawa