Results 51 to 60 of about 35,082 (263)

Unifying dark matter and dark energy with non-canonical scalars

European Physical Journal C: Particles and Fields, 2021
Non-canonical scalar fields with the Lagrangian $${{\mathcal {L}}} = X^\alpha - V(\phi )$$ L = X α - V ( ϕ ) , possess the attractive property that the speed of sound, $$c_s^{2} = (2\,\alpha - 1)^{-1}$$ c s 2 = ( 2 α - 1 ) - 1 , can be exceedingly small ...
Swagat S. Mishra, Varun Sahni
doaj   +1 more source

Rapid terrestrial weathering of the CI1 carbonaceous chondrite find Oued Chebeika 002

Meteoritics &Planetary Science, EarlyView.
Abstract Alteration of historic CI1 meteorite falls during their curation demonstrates the susceptibility of smectite‐rich carbonaceous chondrites to terrestrial exposure. The discovery of Oued Chebeika 002 in Morocco in June 2024 presents a unique opportunity to document the earliest stages of weathering of a CI1 find.
Martin R. Lee, Jasper Glazer
wiley   +1 more source

Einstein and Rastall theories of gravitation in comparison

European Physical Journal C: Particles and Fields, 2018
We profit by a recent paper of Visser claiming that Rastall gravity is equivalent to Einstein gravity to compare the two gravitational theories in a general way. Our conclusions are different from Visser’s ones.
F. Darabi, H. Moradpour, I. Licata, Y. Heydarzade, C. Corda   +4 more
doaj   +1 more source

Pure Gauss–Bonnet NUT black hole with and without non-central singularity

European Physical Journal C: Particles and Fields, 2021
It is known that NUT solution has many interesting features and pathologies like being non-singular and having closed timelike curves. It turns out that in higher dimensions horizon topology cannot be spherical but it has instead to be product of 2 ...
Sajal Mukherjee, Naresh Dadhich
doaj   +1 more source

Sampling the volcanic plumes at Io: Impact speeds and shock conditions

Meteoritics &Planetary Science, EarlyView.
Abstract The desire to sample material from the interior of Io, by flying through its volcanic plumes, requires consideration of the flyby speed and the types of sample collection techniques that can be utilized. Low speed collection (1–2.5 km s−1) would require an orbit around Io itself, which is unlikely due to the accumulated radiation dose that ...
M. J. Burchell, R. C. Ogliore, P. J. Wozniakiewicz   +2 more
wiley   +1 more source

Apriti Cielo: the public’s astronomical imagery as a key to evaluate a museum project (Italian original version) [PDF]

JCOM: Journal of Science Communication, 2006
An effective communication of astronomy cannot take place without considering the view the general public has on the universe. Through a number of narrative interviews with non-experts, a research was carried out on personal cosmologies, to outline the ...
Stefano Giovanardi
doaj  

Hard X-ray and Soft Gamma Ray Polarimetry with CdTe/CZT Spectro-Imager

Galaxies, 2018
CdTe/CZT based spectroscopic two-dimensional (2D)/three-dimensional (3D) imagers when operated in the Compton regime can work as high performance scattering polarimeters, for high-energy astrophysics.
Ezio Caroli, Miguel Moita, Rui M. Curado da Silva, Stefano Del Sordo, Giovanni de Cesare, Jorge M. Maia, Marcela Pàscoa   +6 more
doaj   +1 more source

New evidence on the formation conditions of the Libyan Desert Glass (Western Egypt): Clues from a dendritic zircon inclusion

Meteoritics &Planetary Science, EarlyView.
Abstract Libyan Desert Glass (LDG) is an ~29 million years old, silica‐rich glass found in Western Egypt. Whether this glass formed in an impact cratering context associated with the hypervelocity collision of a cometary/asteroidal body or radiative heating during an airburst is debated. Determination of the formation temperatures and pressures of rare
Niccolò Magnani, Enrico Mugnaioli, Sofia Lorenzon, Lidia Pittarello, Tatiana E. Gorelik, Matteo Masotta, Luigi Folco   +6 more
wiley   +1 more source

Geochemical and petrographic re‐evaluation of ungrouped iron meteorites from Western Australia

Meteoritics &Planetary Science, EarlyView.
Abstract Under the current classification scheme, ungrouped irons make up ~11% of all recognized iron meteorites. A further ~7% of iron meteorites are currently classified as simply “irons” and are yet to be fully classified. To potentially classify these meteorites, newer approaches, including either statistical modeling or advanced geochemical ...
Ashley Rogers, Lucy Forman, Kai Rankenburg, Rachel Kirby, Martin Danišík, Victoria Cousins, Gretchen K. Benedix   +6 more
wiley   +1 more source

An atomic clock synchronized versatile all-in-one digital ‘LockBox’

Scientific Reports
A reliable and robust active stabilization of different control parameters is key to the success of many experiments. The essential hardware for that; lock-in detection, RF generator, and proportional-integral-derivative feedback control should have ...
S. Johnson, S. Das Gupta, T. R. Saravanan, S. Banerjee, S. Majhi, S. De   +5 more
doaj   +1 more source