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Related papers: Probing light relics through cosmic dawn

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A recent observation by the EDGES collaboration shows a strong absorption signal in the global 21-cm spectrum from around a redshift of $z = 17$. This absorption is stronger than the maximum prediction by existing models and indicates that…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-11 Suman Chatterjee , Somnath Bharadwaj

In this review article, we briefly outline our current understanding of the physics associated with the HI 21-cm signal from cosmic dawn. We discuss different phases of cosmic dawn as the ambient gas and the background radiations evolve…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Ankita Bera , Raghunath Ghara , Atrideb Chatterjee , Kanan K. Datta , Saumyadip Samui

Current measurements of the large-scale structure of galaxies are able to place an $\sim 0.5 ~ \rm eV$ upper limit on the absolute mass scale of neutrinos. An order-of-magnitude improvement in raw sensitivity, together with an insensitivity…

Astrophysics · Physics 2009-11-13 F. B. Abdalla , S. Rawlings

Observations of the redshifted 21-cm line of atomic hydrogen have resulted in several upper limits on the 21-cm power spectrum and a tentative detection of the sky-averaged signal at $z\sim17$. Made with the EDGES Low-Band antenna, this…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-02 H. T. J. Bevins , A. Fialkov , E. de Lera Acedo , W. J. Handley , S. Singh , R. Subrahmanyan , R. Barkana

The present-day Universe is seemingly dominated by dark energy and dark matter, but mapping the normal (baryonic) content remains vital for both astrophysics - understanding how galaxies form - and astro-particle physics - inferring…

Cosmological observations allow to measure the abundance of light relics produced in the early Universe. Most studies focus on the thermal freeze-out scenario, yet light relics produced by freeze-in are generic for models in which new light…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-16 Luca Caloni , Patrick Stengel , Massimiliano Lattanzi , Martina Gerbino

We have derived new bounds on the relativistic energy density in the Universe from cosmic microwave background (CMB), large scale structure (LSS), and type Ia supernova (SNI-a) observations. In terms of the effective number of neutrino…

Astrophysics · Physics 2009-11-13 Steen Hannestad

Modern machine learning techniques can unlock the vast cosmological information encoded in forthcoming Square Kilometre Array (SKA) observations. We show that tomographic 21 cm data from the reionisation era can yield stringent tests of…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-19 Benedikt Schosser , Caroline Heneka , Björn Malte Schäfer

In this work, we investigate what role the redshift drift data of Square Kilometre Array (SKA) will play in the cosmological parameter estimation in the future. To test the constraint capability of the redshift drift data of SKA-only, the…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-08 Yan Liu , Jing-Fei Zhang , Xin Zhang

Cosmological measurements over the next decade will enable us to shed light on the content and evolution of the Universe. Complementary measurements of the Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations are expected to…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-10 Siddharth Mishra-Sharma , David Alonso , Joanna Dunkley

Over the next few years the new radio telescopes, such as the Low Frequency Array (LOFAR) will greatly enhance our knowledge of the active history of the Universe. Large-area surveys with these new telescopes will no longer be dominated by…

Astrophysics · Physics 2007-05-23 Matt J. Jarvis

The Planck CMB experiment has delivered the best constraints so far on primordial non-Gaussianity, ruling out early-Universe models of inflation that generate large non-Gaussianity. Although small improvements in the CMB constraints are…

We present a method to measure the small-scale matter power spectrum using high-resolution measurements of the gravitational lensing of the Cosmic Microwave Background (CMB). To determine whether small-scale structure today is suppressed on…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-16 Ho Nam Nguyen , Neelima Sehgal , Mathew Madhavacheril

Measurements of weak gravitational lensing using the cosmic microwave background and the shapes of galaxies have refined our understanding of the late-time history of the Universe. While optical surveys have been the primary source for…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-20 Alba Kalaja , Ian Harrison , William R Coulton

HI 21~cm absorption spectroscopy provides an excellent probe of the neutral gas content of absorbing galaxies, yielding information on their kinematics, mass, physical size and ISM conditions. The high sensitivity, unrivaled frequency…

Astrophysics · Physics 2009-11-10 N. Kanekar , F. H. Briggs

In the next few years, the 21cm line will enable direct observations of the Dark Ages, Cosmic Dawn, and Reionization, which represent previously unexplored periods in our cosmic history. With a combination of sky-averaged global signal…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-20 Adrian Liu , H. Cynthia Chiang , Abigail Crites , Jonathan Sievers , Renée Hložek

The 21 cm intensity mapping (IM) technique provides us with an efficient way to observe the cosmic large-scale structure (LSS). From the LSS data, one can use the baryon acoustic oscillation and redshift space distortion to trace the…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-07 Peng-Ju Wu , Yichao Li , Jing-Fei Zhang , Xin Zhang

The 21-cm signal holds the key to understanding the first structure formation during cosmic dawn. Theoretical progress over the last decade has focused on simulations of this signal, given the nonlinear and nonlocal relation between initial…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-06 Julian B. Muñoz

Weak gravitational lensing of the 21 cm radiation is expected to be an important cosmological probe for post-reionization physics. We investigate the reconstruction of the matter density perturbations using a quadratic minimum variance…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-10 Priyesh Chakraborty , Anthony R. Pullen