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Related papers: Modeling HI at the field level

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HI intensity mapping data traces the large-scale structure matter distribution using the integrated emission of neutral hydrogen gas (HI). The cross-correlation of the intensity maps with optical galaxy surveys can mitigate foreground and…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-28 L. Wolz , S. G. Murray , C. Blake , J. S. Wyithe

Perturbation theory (PT) has been used to interpret the observed nonlinear large-scale structure statistics at the quasi-linear regime. To facilitate the PT-based analysis, we have presented the GridSPT algorithm, a grid-based method to…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-18 Atsushi Taruya , Takahiro Nishimichi , Donghui Jeong

The High Latitude Spectroscopic Survey (HLSS) is the reference baseline spectroscopic survey for NASA's Nancy Grace Roman space telescope, measuring redshifts of $\sim 10$M H$\alpha$ emission line galaxies over a $2000$ deg$^2$ footprint at…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Kevin S. McCarthy , Zhongxu Zhai , Yun Wang

We investigate the column density distribution function of neutral hydrogen at redshift z = 3 using a cosmological simulation of galaxy formation from the OverWhelmingly Large Simulations (OWLS) project. The base simulation includes…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-04 Gabriel Altay , Tom Theuns , Joop Schaye , Neil H. M. Crighton , Claudio Dalla Vecchia

Reliable forecasting of Global Horizontal Irradiance (GHI) is essential for mitigating the variability of solar energy in power grids. This study presents a comprehensive benchmark of ten deep learning architectures for short-term (1-hour…

Machine Learning · Computer Science 2026-01-01 Tin Hoang

Considering the upcoming OWFA, we use simulations of the foregrounds and the $z = 3.35$ HI 21-cm intensity mapping signal to identify the $(k_{\perp},k_{\parallel})$ modes where the expected 21-cm power spectrum $P(k_{\perp},k_{\parallel})$…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-21 Suman Chatterjee , Somnath Bharadwaj , Visweshwar Ram Marthi

Previous work has suggested that perturbation theory is unreliable for Higgs- and Goldstone-boson scattering, at energies above the Higgs mass, for relatively small values of the Higgs quartic coupling $\lambda(\mu)$. By performing a…

High Energy Physics - Phenomenology · Physics 2014-11-17 Kurt Riesselmann , Scott Willenbrock

We construct a simple but self-consistent analytic ionization model for rapid exploration of 21cm power spectrum observables in redshift space. It is fully described by the average ionization fraction $x_e(z)$ and HII patch size $R(z)$ and…

Astrophysics · Physics 2009-11-13 Xiaomin Wang , Wayne Hu

Numerical simulations show that redshift space distortions (RSD) introduce strong scale dependence in the power spectra of halos, with ten percent deviations relative to linear theory predictions even on relatively large scales (k<0.1h/Mpc)…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Zvonimir Vlah , Uroš Seljak , Teppei Okumura , Vincent Desjacques

It has been suggested recently that the appparent accelerated expansion of the universe could be explained by a bias in the SNIa measurements. Such events indeed occur mainly in overdense regions, where matter is located, and whose dynamics…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-06 Vincent Deledicque

We analyze scale dependence of redshift space bias $b$ and $\beta \equiv \Omega_m^{0.6}/b$ in the context of the halo model. We show that linear bias is a good approximation only on large scales, for $k<0.1h$Mpc$^{-1}$. On intermediate…

Astrophysics · Physics 2009-10-31 Uros Seljak

We present a new prescription for the halo mass function (HMF) built upon the Evolution Mapping framework. This approach provides a physical motivation to parametrise the non-universality of the HMF in terms of the recent history of…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-24 Andrea Fiorilli , Andrés N. Ruiz , Ariel G. Sanchez , Matteo Esposito

Distribution of cold gas in the post-reionization era provides an important link between distribution of galaxies and the process of star formation. Redshifted 21 cm radiation from the Hyperfine transition of neutral Hydrogen allows us to…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Bharat Kumar Gehlot , Jasjeet Singh Bagla

Intensity mapping (IM) of spectral lines has the potential to revolutionize cosmology by increasing the total number of observed modes by several orders of magnitude compared to the cosmic microwave background (CMB) anisotropies. In this…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-22 Jurek B. Bauer , David J. E. Marsh , Renée Hložek , Hamsa Padmanabhan , Alex Laguë

After the Higgs boson discovery, LHC can be used as a precision machine to explore its properties. Indeed, in case new resonances will not be found, the only access to New Physics would be via measuring small deviations from the SM…

High Energy Physics - Phenomenology · Physics 2017-05-16 Massimiliano Grazzini , Agnieszka Ilnicka , Michael Spira , Marius Wiesemann

We continue to build support for the proposal to use HII galaxies (HIIGx) and giant extragalactic HII regions (GEHR) as standard candles to construct the Hubble diagram at redshifts beyond the current reach of Type Ia supernovae. Using a…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Jun-Jie Wei , Xue-Feng Wu , Fulvio Melia

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

Accurate optical redshifts will be critical for spectral co-adding techniques used to extract detections from below the noise level in ongoing and upcoming surveys for HI, which will extend our current understanding of gas reservoirs in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Natasha Maddox , Kelley M. Hess , S. -L. Blyth , M. J. Jarvis

Accurate photometric redshift estimation is critical for observational cosmology, especially in large-scale surveys where spectroscopic measurements are impractical. Traditional approaches include template fitting and machine learning, each…

Instrumentation and Methods for Astrophysics · Physics 2026-04-15 Jonas Chris Ferrao , Dickson Dias , Pranav Naik , Glory D'Cruz , Anish Naik , Siya Khandeparkar , Manisha Gokuldas Fal Dessai

With new atomic-hydrogen (HI) observations of FAST Extended Atlas of Selected Targets Survey (FEASTS), we present the first statistical comparison of HI morphology between observations and cosmological simulations, focusing on low-column…

Astrophysics of Galaxies · Physics 2026-02-04 Xuchen Lin , Jing Wang , Guinevere Kauffmann , Volker Springel , Rüdiger Pakmor