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Using the full radiation transfer function, we numerically calculate the CMB angular bispectrum seeded by the compensated magnetic scalar density mode. We find that, for the string inspired primordial magnetic fields characterized by index…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 Rong-Gen Cai , Bin Hu , Hong-Bo Zhang

We investigate bounds on the strength of the primordial magnetic field (PMF) from the cosmic microwave background (CMB) bispectra of the intensity (temperature) modes induced from the auto- and cross-correlated bispectra of the scalar and…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-02 Maresuke Shiraishi , Daisuke Nitta , Shuichiro Yokoyama , Kiyotomo Ichiki

Spatially fluctuating primordial magnetic fields (PMFs) inhomogeneously reheat the Universe when they dissipate deep inside the horizon before recombination. Such an energy injection turns into an additional photon temperature perturbation.…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-28 Shohei Saga , Atsuhisa Ota , Hiroyuki Tashiro , Shuichiro Yokoyama

We explore the ways in which primordial magnetic fields influence the thermal and ionization history of the post-recombination universe. After recombination the universe becomes mostly neutral resulting also in a sharp drop in the radiative…

Astrophysics · Physics 2008-11-26 Shiv K. Sethi , Kandaswamy Subramanian

We study the prospects for extracting cosmological and astrophysical parameters from the low radio frequency 21-cm background due to the spin-flip transition of neutral Hydrogen during and prior to the reionization of the Universe. We make…

Astrophysics · Physics 2009-11-11 Mario G. Santos , Asantha Cooray

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

In inflationary models with minimal amount of gravity waves, the primordial power spectrum of density fluctuations, $A_S^2(k)$, together with the basic cosmological parameters, completely specify the predictions for the cosmic microwave…

Astrophysics · Physics 2009-10-31 Yun Wang , David N. Spergel , Michael A. Strauss

The redshifted 21-cm emission by neutral hydrogen offers a unique tool for mapping structure formation in the early universe in three dimensions. Here we provide the first detailed calculation of the 21-cm emission signal during and after…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Anastasia Fialkov , Abraham Loeb

(Abridged) This paper introduces the formalism which connects between rotation measure ($\RM$) measurements for extragalactic sources and the cosmological magnetic field power spectrum. It is shown that the amplitude and shape of the…

Astrophysics · Physics 2016-08-30 Tsafrir Kolatt

A primordial magnetic field with the strength in the 1-10 pG range can resolve the tension between different measurements of the Hubble constant and provide an explanation for the excess opacity in the 21 cm line at redshift $15<z<20$, if…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-22 A. Korochkin , O. Kalashev , A. Neronov , D. Semikoz

Mainly used to set constraints on cosmological parameters, CMB anisotropies can give information on primordial universe. Unfortunately, initial conditions and late time cosmology are degenerated. I focus on the effect of the shape of the…

Astrophysics · Physics 2007-05-23 Marian Douspis

Although the cosmological paradigm based on cold dark matter and adiabatic, nearly scale-invariant primordial fluctuations is consistent with a wide variety of existing observations, it has yet to be sufficiently tested on scales smaller…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-16 Hayato Shimabukuro , Kiyotomo Ichiki , Susumu Inoue , Shuichiro Yokoyama

Linear theory predicts that primordial magnetic fields (PMFs) enhance the matter power spectrum on small scales. However, the linear approximation breaks down on sufficiently small scales where PMF-induced baryon perturbations back-react…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-13 Pranjal Ralegankar , Enrico Garaldi , Matteo Viel

The {\em Planck} DR3 measurements of the temperature and polarization anisotropies power spectra of the cosmic microwave background (CMB) show an excess of smoothing of the acoustic peaks with respect to $\Lambda$CDM, often quantified by a…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-26 Mario Ballardini , Fabio Finelli

Fluctuations of the 21 cm brightness temperature before the formation of the first stars hold the promise of becoming a high-precision cosmological probe in the future. The growth of over densities is very well described by perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-23 Yacine Ali-Haïmoud , P. Daniel Meerburg , Sihan Yuan

The matter power spectrum has been strongly constrained by astronomical measurements at large scales, but only weakly at small scales. Compared with the standard scenario, the deviation of the matter power spectrum at small scales has…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-12 Yupeng Yang , Xiujuan Li , Gang Li

We explore the complete history of the 21-cm signal in the redshift range z = 7-40. This redshift range includes various epochs of cosmic evolution related to primordial star formation, and should be accessible to existing or planned…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Anastasia Fialkov , Rennan Barkana

This paper presents a measurement of the angular power spectrum of the Cosmic Microwave Background from l=75 to l=1025 (~10' to 5 degrees) from a combined analysis of four 150 GHz channels in the BOOMERANG experiment. The spectrum contains…

Magnetic fields appear wherever plasma and currents can be found. As such, they thread through all scales in Nature. It is natural, therefore, to suppose that magnetic fields might have been formed within the high temperature environments…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-16 Dai G. Yamazaki , Toshitaka Kajino , Grant J. Mathew , Kiyotomo Ichiki

Magnetic fields appear to be a generic feature of the early universe and are a natural source of secondary CMB non-Gaussianity. In recent years the statistical nature of the stresses of a primordial magnetic field has been well studied. In…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Iain A. Brown
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