Results 31 to 40 of about 27,730 (253)
Polarity Asymmetries in Rocket‐Triggered Lightning
Geophysical Research Letters, Volume 50, Issue 17, 16 September 2023., 2023 Abstract The dissonant development of positive and negative lightning leaders is a central question in atmospheric electricity. It is also the likely root cause of other reported asymmetries between positive and negative lightning flashes, including the ones regarding: stroke multiplicity, recoil activity, leader velocities, and emission of energetic ...
C. L. da Silva +10 more
wiley +1 more source
The Astrophysical Journal, 2023 Baryons both increase halo concentration through adiabatic contraction and expel mass through feedback processes. However, it is not well understood how the radiation fields prevalent during the epoch of reionization affect the evolution of concentration
Hanjue Zhu, Nickolay Y. Gnedin
doaj +1 more source
Annalen der Physik, Volume 535, Issue 7, July 2023., 2023 Implications for the cosmological model are explored of the assumption that the cosmic microwave background is subject to an SU(2) Yang– Mills theory of scale 10−4 eV rather than U(1) quantum thermodynamics. This concerns zeroth‐order (changes at high redshifts) and first‐order cosmological perturbations (changes at high and low redshifts).
Ralf Hofmann +2 more
wiley +1 more source
Dark Energy from Cosmological Energy Conservation
Advances in Astronomy, Volume 2023, Issue 1, 2023., 2023 The value of the gravitational wave energy density is unknown. Current progress in gravitational wave detection suggests that the energy density of the stochastic gravitational wave background (SGWB) will be estimated in the next decades. A derivation of its value is presented under the assumption that energy lost due to cosmic redshift is fully ...
Manuel Uruena Palomo, Rubab Manzoor
wiley +1 more source
Living Reviews in Computational Astrophysics, 2022 AbstractThe transformation of cold neutral intergalactic hydrogen into a highly ionized warm plasma marks the end of the cosmic dark ages and the beginning of the age of galaxies. The details of this process reflect the nature of the early sources of radiation and heat, the statistical characteristics of the large-scale structure of the Universe, the ...
Nickolay Y. Gnedin, Piero Madau
openaire +2 more sources
Progress and Challenges in Electromechanical Coupling of Radio Telescopes
International Journal of Antennas and Propagation, Volume 2022, Issue 1, 2022., 2022 Radio astronomy is a discipline of dynamics and wonders. The vast universe has many secrets to unravel. As one of the important facilities in this discipline, radio telescopes play a key role in collecting astronomical data and unraveling mysteries.
Yuefei Yan +10 more
wiley +1 more source
Searching for the reionization sources [PDF]
Monthly Notices of the Royal Astronomical Society: Letters, 2007 Abstract Using a reionization model simultaneously accounting for a number of experimental data sets, we investigate the nature and properties of reionization sources. Such a model predicts that hydrogen reionization starts at z≈ 15, is initially driven by metal-free (Population III) stars, and is 90 per cent complete by z≈ 8.
Choudhury, T. Roy, FERRARA, ANDREA
openaire +4 more sources
A (conditional) role for labdane‐related diterpenoid natural products in rice stomatal closure
New Phytologist, Volume 230, Issue 2, Page 698-709, April 2021., 2021 Summary Rice (Oryza sativa) is the staple food for over half the world’s population. Drought stress imposes major constraints on rice yields. Intriguingly, labdane‐related diterpenoid (LRD) phytoalexins in maize (Zea mays) affect drought tolerance, as indicated by the increased susceptibility of an insertion mutant of the class II diterpene cyclase ...
Juan Zhang +9 more
wiley +1 more source
Early Reionization by Miniquasars [PDF]
The Astrophysical Journal, 2004 Motivated by the recent detection by WMAP of a large optical depth to Thomson scattering -- implying a very early reionization epoch -- we assess a scenario where the universe was reionized by `miniquasars' powered by intermediate-mass black holes (IMBHs), the remnants of the first generation of massive stars.
S. P. Oh +5 more
openaire +6 more sources
Crossing the Rubicon of Reionization with z ∼ 5 QSOs
The Astrophysical Journal, 2023 One of the key open questions in cosmology is the nature of sources that completed cosmological hydrogen reionization at z ∼ 5.2. High- z primeval galaxies have been long considered the main drivers of reionization, with a minor role played by high- z ...
Andrea Grazian +14 more
doaj +1 more source