Results 31 to 40 of about 688,478 (251)

Measurements of the Matter Density Perturbation Amplitude from Cosmological Data [PDF]

Astronomy letters, 2018
The various measurements of the linear matter density perturbation amplitude obtained from the observations of the cosmic microwave background (CMB) anisotropy, weak gravitational lensing, galaxy cluster mass function, matter power spectrum, and redshift
R. Burenin
semanticscholar   +1 more source

Investigation of the Surface Brightness Model in the Milky Way via Homotopy Perturbation Method

Journal of Applied Mathematics and Physics, 2020
In this paper, a linear delay model in astronomy, called as Ambartsumian equation, is investigated by two different approaches. The first is the approximate homotopy perturbation method (HPM), while the second is a new closed-form solution for this ...
Abdullah A. Alatawi, M. Aljoufi, Fahad M. Alharbi, Abdelhalim Ebaid   +3 more
semanticscholar   +1 more source

Potential impact of subsonic and supersonic aircraft exhaust on water vapor in the lower stratosphere assessed via a trajectory model [PDF]

, 2003
We employ a trajectory model to assess the impact on the stratosphere of water vapor present in the exhaust of subsonic and a proposed fleet of supersonic aircraft.
Jackman, Charles A., Morris, Gary A., Rosenfield, Joan A, Schoeberl, Mark R.   +3 more
core   +3 more sources

Short-axis-mode rotation of a free rigid body by perturbation series [PDF]

, 2013
A simple rearrangement of the torque free motion Hamiltonian shapes it as a perturbation problem for bodies rotating close to the principal axis of maximum inertia, independently of their triaxiality.
Lara, Martin
core   +1 more source

Gravitational wave astronomy with radio galaxy surveys [PDF]

, 2016
In the next decade, new astrophysical instruments will deliver the first large-scale maps of gravitational waves and radio sources. Therefore, it is timely to investigate the possibility to combine them to provide new and complementary ways to study the ...
A. Raccanelli
semanticscholar   +1 more source

The properties of the local spiral arms from RAVE data: two-dimensional density wave approach [PDF]

, 2012
Using the RAVE survey, we recently brought to light a gradient in the mean galactocentric radial velocity of stars in the extended solar neighbourhood.
A. Helmi, A. Just, A. Siebert, A. Siviero, Adler, Antoja, B. Burnett, B. Famaey, B. K. Gibson, Benjamin, Bertin, Binney, Binney, Binney, Bissantz, Breddels, Burnett, C. Boeche, C. Faure, Churchwell, De Simone, Dehnen, Dehnen, Drimmel, Drimmel, E. K. Grebel, Englmaier, Famaey, Foyle, G. Seabroke, Georgelin, Gerhard, Grand, I. Minchev, J. Binney, J. Bland-Hawthorn, J. F. Navarro, Kendall, Lin, Lin, Lowe, Lépine, Lépine, M. E. K. Williams, M. Steinmetz, McMillan, Minchev, Moni-Bidin, O. Bienaymé, Pompéia, Q. A. Parker, Quillen, Quillen, Reid, Salo, Schönrich, Sellwood, Sellwood, Sellwood, Shetty, Shu, Siebert, Siebert, Smith, Smith, Stanek, Steinmetz, Struck, T. Zwitter, U. Munari, Vallée, Voglis, W. A. Reid, Widrow, Zwitter, Zwitter   +75 more
core   +6 more sources

Metric tensor formulation of strain in density-functional perturbation theory [PDF]

, 2004
The direct calculation of the elastic and piezoelectric tensors of solids can be accomplished by treating homogeneous strain within the framework of density-functional perturbation theory.
D. Hamann, Xifan Wu, K. Rabe, D. O. D. O. Physics, Astronomy, Rutgers University, Piscataway, Nj, Bell Laboratories, Lucent Technologies, M. Hill, Mat-Sim Research Llc   +11 more
semanticscholar   +1 more source

On the nature of an ejection event in the jet of 3C111

, 2008
We present a possible scenario for the ejection of a superluminal component in the jet of the Broad Line Radio Galaxy 3C111 in early 1996. VLBI observations at 15 GHz discovered the presence of two jet features on scales smaller than one parsec.
Agudo, Aloy, E. Ros, Fender, Grandi, Gómez, I. Agudo, J. L. Gómez, Kadler, Kellermann, Lister, M. Kadler, M. Perucho, Marscher, Marscher, Marscher, Martí, Mirabel, Perucho, Savolainen, Y. Y. Kovalev   +20 more
core   +1 more source

Multi-process driven unusually large equatorial perturbation electric fields during the April 2023 geomagnetic storm

Frontiers in Astronomy and Space Sciences
The low latitude ionosphere and thermosphere are strongly disturbed during and shortly after geomagnetic storms. We use novel Jicamarca radar measurements, ACE satellite solar wind, and SuperMAG geomagnetic field observations to study the electrodynamic ...
B. Fejer, Sophia R. Laranja, P. Condor
semanticscholar   +1 more source

NANOGrav hints on planet-mass primordial black holes [PDF]

Science China Physics Mechanics and Astronomy, 2020
Recently, the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) claimed the detection of a stochastic common-spectrum process of the pulsar timing array (PTA) time residuals from their 12.5 year data, which might be the first ...
Guillem Domènech, Shi Pi
semanticscholar   +1 more source