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Measurements of 21 cm line fluctuations from minihalos have been discussed as a powerful probe of a wide range of cosmological models. However, previous studies have taken into account only the pixel variance, where contributions from…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-14 Toyokazu Sekiguchi , Tomo Takahashi , Hiroyuki Tashiro , Shuichiro Yokoyama

Current and upcoming wide-field surveys for weak gravitational lensing and the Sunyaev-Zel'dovich effect will generate mass-selected catalogues of dark matter halos with internal or followup photometric redshift information. The angular…

Astrophysics · Physics 2009-11-06 Asantha Cooray , Wayne Hu , Dragan Huterer , Michael Joffre

The correlation between 21cm fluctuations and galaxies is sensitive to the astrophysical properties of the galaxies that drove reionization. Thus, detailed measurements of the cross-power spectrum and its evolution could provide a powerful…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Jaehong Park , Han-Seek Kim , J. Stuart B. Wyithe , C. G. Lacey

Detecting a deviation from a featureless primordial power spectrum of fluctuations would give profound insight into the physics of the primordial Universe. Depending on their nature, primordial features can either provide direct evidence…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-28 Xingang Chen , P. Daniel Meerburg , Moritz Münchmeyer

The tomographic Alcock-Paczynski (AP) test is a robust large-scale structure (LSS) measurement that receives little contamination from the redshift space distortion (RSD). It has placed tight cosmological constraints by using small and…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-24 Xiao-Dong Li , Haitao Miao , Xin Wang , Xue Zhang , Feng Fang , Xiaolin Luo , Qing-Guo Huang , Miao Li

The reported detection of the global 21-cm signal by the EDGES collaboration is significantly stronger than standard astrophysical predictions. One possible explanation is an early radio excess above the cosmic microwave background. Such a…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-12 Sudipta Sikder , Rennan Barkana , Anastasia Fialkov , Itamar Reis

One of the main problems of observational cosmology is to determine the range in which a reliable measurement of galaxy correlations is possible. This corresponds to determine the shape of the correlation function, its possible evolution…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Francesco Sylos Labini , Daniil Tekhanovich , Yurij V. Baryshev

Measurements from the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission 2 (ARCADE-2) reveal a strong radio background in the GHz frequency range. Since the cosmological 21-cm signal is measured relative to the background…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-17 Sudipta Sikder , Rajesh Mondal , Rennan Barkana , Anastasia Fialkov

We present the most detailed computation to date of the 21-cm global signal and fluctuations at $z\gtrsim 500$. Our calculations include a highly precise estimate of the Wouthuysen-Field (WF) effect and the first explicit calculation of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-29 Patrick C. Breysse , Yacine Ali-Haïmoud , Christopher M. Hirata

Measurements of the 21cm line emission by residual cosmic hydrogen after reionization can be used to trace the power spectrum of density perturbations through a significant fraction of the observable volume of the Universe. We show that a…

Astrophysics · Physics 2009-06-23 Abraham Loeb , Stuart Wyithe

The clustering pattern in high redshift HI maps is expected to be anisotropic due to two distinct reasons, the Alcock-Paczynski effect and the peculiar velocities, both of which are sensitive to the cosmological parameters. The signal is…

Astrophysics · Physics 2016-08-30 Sk. Saiyad Ali , Somnath Bharadwaj , Biswajit Pandey

The apparent anisotropies of the galaxy clustering in observable redshift space provide a unique opportunity to simultaneously probe cosmic expansion and gravity on cosmological scales via the Alcock--Paczynski effect and redshift-space…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-25 Yong-Seon Song , Atsushi Taruya , Akira Oka

The 21-cm signal from the Cosmic Dawn (CD) is likely to contain large fluctuations, with the most extreme astrophysical models on the verge of being ruled out by observations from radio interferometers. It is therefore vital that we…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-21 Hannah E. Ross , Sambit K. Giri , Keri L. Dixon , Raghunath Ghara , Ilian T. Iliev , Garrelt Mellema

We propose the use of angular fluctuations in the galaxy redshift field as a new way to extract cosmological information in the Universe. This new probe $\delta z (\hat{n})$ consists on the statistics of sky maps built by projecting…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-07 Carlos Hernandez-Monteagudo , Jonas Chaves-Montero , Raul E. Angulo

Radio sources are expected to have formed at high redshifts, producing an excess radiation background above the cosmic microwave background (CMB) at low frequencies. Their effect on the redshifted 21-cm signal of neutral hydrogen is usually…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-28 Itamar Reis , Anastasia Fialkov , Rennan Barkana

The shape of the angular power spectrum of galaxies in the linear regime is defined by the horizon size at the matter-radiation equality. When calibrated by cosmic microwave background measurements, the shape of the clustering spectrum can…

Astrophysics · Physics 2011-02-11 Asantha Cooray

The 21-cm absorption feature reported by the EDGES collaboration is several times stronger than that predicted by traditional astrophysical models. If genuine, a deeper absorption may lead to stronger fluctuations on the 21-cm signal on…

The cosmological peculiar velocity field (deviations from the pure Hubble flow) of matter carries significant information on dark energy, dark matter and the underlying theory of gravity on large scales. Peculiar motions of galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-17 Adi Nusser , Enzo Branchini , Martin Feix

The luminosity distance vs. redshift law is now measured using supernovae and gamma ray bursts, and the angular size distance is measured at the surface of last scattering by the CMB and at z = 0.35 by baryon acoustic oscillations. In this…

Astrophysics · Physics 2011-02-11 Edward L. Wright

One of the main challenges for future 21 cm observations is to remove foregrounds which are several orders of magnitude more intense than the HI signal. We propose a new technique for removing foregrounds of the redshifted 21 cm…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Jungyeon Cho , A. Lazarian , P. Timbie