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The free-electron population during the reionized epoch rescatters CMB temperature quadrupole and generates a now well-known polarization signal at large angular scales. While this contribution has been detected in the…

Astrophysics · Physics 2009-11-10 Asantha Cooray

We study the cosmic variance limit on constraining primordial non-Gaussianity for a variety of theory-motivated shapes. We consider general arguments for 2D and 3D surveys, with a particular emphasis on the CMB. A scale-invariant $N$-point…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-11 Alba Kalaja , P. Daniel Meerburg , Guilherme L. Pimentel , William R. Coulton

We calculate the secondary anisotropies in the CMB produced by inhomogeneous reionization from simulations in which the effects of radiative and stellar feedback effects on galaxy formation have been included. This allows to…

Astrophysics · Physics 2009-10-31 M. Bruscoli , A. Ferrara , R. Fabbri , B. Ciardi

Cross-correlations between 21cm observations and galaxy surveys provide a powerful probe of reionization by reducing foreground sensitivity while linking ionization morphology to galaxies. We quantify the constraining power of 21cm-Galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-27 Yannic Pietschke , Anne Hutter , Caroline Heneka

Local non-Gaussianities in the initial conditions of the Universe, parameterized by $f_{\rm NL}$, induce a scale-dependence in the large-scale bias of halos in the late Universe. This effect is a promising path to constrain multi-field…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-04 Fiona McCarthy , Mathew S. Madhavacheril , Abhishek S. Maniyar

Multi-field inflation models and non-Bunch-Davies vacuum initial conditions both predict sizeable non-Gaussian primordial perturbations and anisotropic $\mu$-type spectral distortions of the cosmic microwave background (CMB) blackbody.…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-23 Mathieu Remazeilles , Andrea Ravenni , Jens Chluba

A detection or nondetection of primordial non-Gaussianity by using the cosmic microwave background radiation (CMB) offers a way of discriminating inflationary scenarios and testing alternative models of the early universe. This has…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-15 A. Bernui , M. J. Reboucas , A. F. F. Teixeira

We outline the expected constraints on non-Gaussianity from the cosmic microwave background (CMB) with current and future experiments, focusing on both the third (f_{NL}) and fourth-order (g_{NL} and \tau_{NL}) amplitudes of the local…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-27 Joseph Smidt , Alexandre Amblard , Christian T. Byrnes , Asantha Cooray , Alan Heavens , Dipak Munshi

Primordial magnetic fields lead to non-Gaussian signals in the Cosmic Microwave Background (CMB) even at the lowest order, as magnetic stresses, and the temperature anisotropy they induce, depend quadratically on the magnetic field. In…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-03 T. R. Seshadri , Kandaswamy Subramanian

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…

The detection of primordial non-Gaussianity could provide a powerful means to test various inflationary scenarios. Although scale-invariant non-Gaussianity (often described by the $f_{NL}$ formalism) is currently best constrained by the…

Astrophysics · Physics 2009-06-23 Marilena LoVerde , Amber Miller , Sarah Shandera , Licia Verde

Neutral hydrogen is ubiquitous, absorbing and emitting 21 cm radiation throughout much of the Universe's history. Active sources of perturbations, such as cosmic strings, would generate simultaneous perturbations in the distribution of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Aaron Berndsen , Levon Pogosian , Mark Wyman

The timeline of cosmic reionization remains uncertain despite sustained efforts to study how the ionizing output of early galaxies shaped the intergalactic medium (IGM). Using the semi-numerical code LIMFAST, we investigate the prospects…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 Guochao Sun , Adam Lidz , Tzu-Ching Chang , Jordan Mirocha , Steven R. Furlanetto

We study the signal in the Cosmic Microwave Background (CMB) polarization anisotropy resulting from patchy reionization. It is well known that the primordial polarization of the CMB is very sensitive to the details of reionization.…

Astrophysics · Physics 2014-10-13 Guo-Chin Liu , Naoshi Sugiyama , Andrew J. Benson , C. G. Lacey , Adi Nusser

In this paper we analyze the biasing effect of point sources, either thermal Sunyaev-Zeldovich clusters or standard radio sources, on the estimated strength of the non-Gaussianity in the Cosmic Microwave Background (CMB). We show that the…

Astrophysics · Physics 2008-11-26 Daniel Babich , Elena Pierpaoli

Reionization of the cosmic neutral hydrogen by the first stars in the Universe is an inhomogeneous process which produces spatial fluctuations in free electron density. These fluctuations lead to observable signatures in cosmological probes…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-11 Sourabh Paul , Suvodip Mukherjee , Tirthankar Roy Choudhury

Absorption or emission against the cosmic microwave background radiation (CMB) may be observed in the redshifted 21cm line if the spin temperature of the neutral intergalactic medium prior to reionization differs from the CMB temperature.…

Astrophysics · Physics 2009-12-10 Tiziana Di Matteo , Rosalba Perna , Tom Abel , Martin J. Rees

We present a comprehensive set of forecasts for the cross-correlation signal between 21cm intensity mapping and galaxy redshift surveys. We focus on the data sets that will be provided by the SKAO for the 21cm signal, DESI and Euclid for…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-10 Maria Berti , Marta Spinelli , Matteo Viel

We know very little about primordial curvature perturbations on scales smaller than about a Mpc. Measurements of the mu-type distortion of the CMB spectrum provide the unique opportunity to probe these scales over the unexplored range from…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Enrico Pajer , Matias Zaldarriaga

We revisit the potential of 21cm radiation fluctuations, during the epoch of reionization, in constraining the amplitude of local primordial non-Gaussianity (PNG) $f_{\rm NL}^{\rm loc}$. There generically exists an epoch at which the linear…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-29 Nickolas Kokron