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Related papers: Soft Photon Heating: A Semi-Analytic Framework and…

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The inhibition of the total HI $n\leftrightarrow 1$ transition rate by delayed resonant reabsorption of HI $(n+1)\to 1$ photons by HI $n\to 1$ line which is possible due to cosmological redshift is considered semi-analytically. The method…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-22 E. E Kholupenko , A. V. Ivanchik , D. A Varshalovich

Reducing the intrinsic emittance of photocathodes is one of the most promising routes to improving the brightness of electron sources. However, when emittance growth occurs during beam transport (for example, due to space-charge), it is…

We study the dependence of the heat transfer between two semi-infinite solids on the dielectric properties of the bodies. We show that the heat transfer at short separation between the solids may increase by many order of magnitude when the…

Materials Science · Physics 2009-11-11 A. I. Volokitin , B. N. J. Persson

The intergalactic medium is expected to be at its coldest point before the formation of the first stars in the universe. Motivated by recent results from the EDGES experiment, we revisit the standard calculation of the kinetic temperature…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-21 Tejaswi Venumadhav , Liang Dai , Alexander Kaurov , Matias Zaldarriaga

We extend the analysis of Gabor transforms on a Cosmic Microwave Background (CMB) temperature map (Hansen, Gorski and Hivon 2002) to polarisation. We study the temperature and polarisation power spectra on the cut sky, the so-called pseudo…

Astrophysics · Physics 2008-11-26 Frode K. Hansen , Krzysztof M. Gorski

In this paper we consider the re-processing of high frequency photons emitted by HeII and HeI during the epoch of cosmological recombination by HeI and HI. We demonstrate that, in comparison to computations which neglect all feedback…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 J. Chluba , R. A. Sunyaev

We discuss diffractive processes in proton-proton collisions at small momentum transfers without and with photon radiation. We consider the soft exclusive reactions $pp \to pp$, $p\bar{p} \to p\bar{p}$, and $pp \to pp \gamma$ within the…

High Energy Physics - Phenomenology · Physics 2022-08-24 Piotr Lebiedowicz , Otto Nachtmann , Antoni Szczurek

An unprecedented array of new observational capabilities are starting to yield key constraints on models of the epoch of first light in the Universe. In this Letter we discuss the implications of the UV radiation background at cosmic dawn…

The occurrence of radio-frequency (rf) breakdown limits operational electromagnetic gradients in accelerator structures. Experimental evidence often suggests that breakdown events are associated with temperature and dark current spikes on…

Accelerator Physics · Physics 2025-03-05 Ryo Shinohara , Soumendu Bagchi , Evgenya Simakov , Danny Perez , Sergey V. Baryshev

The upcoming radio interferometer Square Kilometre Array (SKA) is expected to directly detect the redshifted 21-cm signal from the neutral hydrogen present during the Cosmic Dawn. Temperature fluctuations from X-ray heating of the neutral…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-15 Hannah E. Ross , Keri L. Dixon , Raghunath Ghara , Ilian T. Iliev , Garrelt Mellema

Cosmic rays generated by supernovae carry away a significant portion of the lifetime energy emission of their parent star, making them a plausible mechanism for heating the early universe intergalactic medium (IGM). Following a review of…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-02 T. Gessey-Jones , A. Fialkov , E. de Lera Acedo , W. J. Handley , R. Barkana

Allowing for enhanced Ly$\alpha$ photon line emission from Population III dominated stellar systems in the first forming galaxies, we show the 21-cm cosmic dawn signal at $10<z<30$ may substantially differ from standard scenarios. Energy…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-06 Avery Meiksin , Piero Madau

We use numerical hydrodynamical simulations of early structure formation in a LCDM universe to investigate the spin temperature and 21cm brightness of the diffuse intergalactic medium (IGM) prior to the epoch of cosmic reionization, at…

Astrophysics · Physics 2009-11-13 Michael Kuhlen , Piero Madau , Ryan Montgomery

In the coming decade, low-frequency radio arrays will begin to probe the epoch of reionization via the redshifted 21-cm hydrogen line. Successful interpretation of these observations will require effective statistical techniques for…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Vera Gluscevic , Rennan Barkana

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

The low-energy electronic recoil spectrum in XENON1T provides an intriguing hint for potential new physics. At the same time, observations of horizontal branch stars favor the existence of a small amount of extra cooling compared to the one…

High Energy Physics - Phenomenology · Physics 2020-11-25 Gonzalo Alonso-Álvarez , Fatih Ertas , Joerg Jaeckel , Felix Kahlhoefer , Lennert J. Thormaehlen

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

Single photons of subnatural linewidth and high spectral brightness are necessary for efficient light-matter interaction at the single photon level, which lies at the heart of many quantum photonic technologies. Here we demonstrate a bright…

We discuss how measurements of fluctuations in the absorption of cosmic microwave background (CMB) photons by neutral gas during the cosmic dark ages, at redshifts z ~ 7--200, could reveal the primordial deuterium abundance of the Universe.…

Astrophysics · Physics 2007-05-23 Kris Sigurdson , Steven R. Furlanetto

Inflationary models that involve bursts of particle production generate bump-like features in the primordial power spectrum of density perturbations. These features influence the evolution of density fluctuations, leaving their unique…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-19 Suvedha Suresh Naik , Pravabati Chingangbam , Saurabh Singh , Andrei Mesinger , Kazuyuki Furuuchi
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