Results 21 to 30 of about 727,398 (339)

Searching for the dark force with 21-cm spectrum in light of EDGES

Physics Letters B, 2019
The EDGES Collaboration has recently announced the detection of the 21-cm spectrum with an absorption profile centred at 78 megahertz, of which the depth is deeper than that expected by the standard cosmological paradigm. To enrich the heating process of
Chunlong Li, Yi-Fu Cai
doaj   +1 more source

Chemistry of heavy elements in the Dark Ages [PDF]

, 2009
Primordial molecules were formed during the Dark Ages, i.e. the time between recombination and reionization in the early Universe. The purpose of this article is to analyze the formation of primordial molecules based on heavy elements during the Dark ...
Abel, Abel, Affleck, Applegate, Barkana, Basu, Basu, Bromm, Burles, C. Winteler, Ciardi, Cyburt, D. Puy, Dolgov, Dubrovich, Dunkley, Fall, Fendt, Field, Flower, Flower, Galli, Glover, Glover, Glover, Harwit, Hindmarsh, Hirata, Huntress, Jedamzik, Khlopov, Komatsu, Kompaneets, Le Bourlot, Lepp, Lepp, Lipovka, M. Signore, Maio, Malaney, Maoli, Maoli, Matsuura, Matsuura, Matsuura, McGreer, Molaro, Nagakura, Omukai, Omukai, P. Vonlanthen, Peebles, Peebles, Pfenniger, Puy, Puy, Puy, Puy, Puy, Péquignot, Rauscher, Ripamonti, Ripamonti, Saslaw, Schleicher, Shchekinov, Signore, Signore, Silk, Songaila, Songaila, Stancil, Stancil, Steigman, T. Rauscher, Tegmark, Uehara, Uehara, V. Dubrovich, Verner, Verner, Woodall, Yoshida   +82 more
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Indirect Dark Matter Signatures in the Cosmic Dark Ages I. Generalizing the Bound on s-wave Dark Matter Annihilation from Planck [PDF]

, 2015
Recent measurements of the cosmic microwave background (CMB) anisotropies by Planck provide a sensitive probe of dark matter annihilation during the cosmic dark ages, and specifically constrain the annihilation parameter $f_\mathrm{eff} \langle \sigma v \
Slatyer, Tracy R.
core   +2 more sources

Sterile dark matter and reionization [PDF]

, 2006
Sterile neutrinos with masses in the keV range can be the dark matter, and their emission from a supernova can explain the observed velocities of pulsars.
Abazajian, Abazajian, Abazajian, Akhmedov, Alexander Kusenko, Arras, Asaka, Asaka, Barkovich, Biermann, Boyarsky, Boyarsky, Boyarsky, Boyarsky, d. Shi, de Gouvea, de Gouvea, Dodelson, Dolgov, Duncan, Duncan, Fryer, Fukugita, Fuller, Gell-Mann, Gelmini, Glashow, Kouveliotou, Kusenko, Kusenko, Kusenko, Kusenko, Kusenko, Kusenko, Mapelli, Mapelli, Minkowski, Mohapatra, Riemer-Sorensen, Ripamonti, Seljak, Shaposhnikov, Socrates, Tegmark, Viel, Viel, Vilenkin, Watson   +47 more
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Britain in the Seventies – Our Unfinest Hour?

Revue Française de Civilisation Britannique, 2017
In popular recollection, the 1970s have gone down as the dark ages, Britain’s gloomiest period since the second world war, set between Harold Wilson’s ‘swinging sixties’ and Margaret Thatcher’s divisive eighties. Forty years on, it is appropriate for the
Kenneth O. Morgan
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Francesco Petrarca and the Parameters of Historical Research

Religions, 2012
Although scholars in the first two generations of humanism wrote the histories drawing heavily on ancient Roman sources, Petrarca was the first humanist historian to focuses on the history of ancient Roma.
Ronald Witt
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The R/renaissance(s), Humanists And Classics

The Journal of Classics Teaching, 2018
First, where does the Renaissance fit in chronologically with other periods of the past? There is general agreement that the Renaissance should be dated from 1300 to 1650, though some believe that a more accurate and meaningful starting date would be ...
Jerome Moran
doaj   +1 more source

Climate Variability in Central Europe during the Last 2500 Years Reconstructed from Four High-Resolution Multi-Proxy Speleothem Records

Geosciences, 2021
The Late Holocene was characterized by several centennial-scale climate oscillations including the Roman Warm Period, the Dark Ages Cold Period, the Medieval Warm Period and the Little Ice Age.
Sarah Waltgenbach, Dana F. C. Riechelmann, Christoph Spötl, Klaus P. Jochum, Jens Fohlmeister, Andrea Schröder-Ritzrau, Denis Scholz   +6 more
doaj   +1 more source

Growing and laying performances of two varieties of Noi chickens raised in an intensive farming system

Vietnam Journal of Science, Technology and Engineering, 2022
This study was conducted to compare the black and dark brown varieties of Noi purebred chickens raised in an intensive farming system. A total of 600 black and 600 dark brown Noi chickens were observed starting from 1 day after hatching.
Vu Hoa Dang, Van Diep Duong, Thi Huong Nguyen, Ngoc Khanh Do, Thi Hue Le, Minh Hieu Nguyen, Thi Ut Tran, Hoang Nguyen Nguyen, Thuy Nhung Dang   +8 more
doaj   +1 more source

The bispectrum of redshifted 21-cm fluctuations from the dark ages [PDF]

, 2006
Brightness-temperature fluctuations in the redshifted 21-cm background from the cosmic dark ages are generated by irregularities in the gas-density distribution and can then be used to determine the statistical properties of density fluctuations in the ...
Ali S., Annalisa Pillepich, Cristiano Porciani, Field G. B., Sabino Matarrese, Scott D.   +5 more
core   +2 more sources