Results 21 to 30 of about 8,399 (150)
On the propagation of the highest energy cosmic ray nuclei [PDF]
, 1998 We study the propagation of ultra-high energy cosmic ray nuclei through the background of cosmic microwave and intergalactic infrared photons, using recent re-estimates for the density of the last ones.
Epele, Luis N., Roulet, Esteban
core +2 more sources
Nearby quasar remnants and ultra-high energy cosmic rays [PDF]
, 2002 As recently suggested, nearby quasar remnants are plausible sites of black-hole based compact dynamos that could be capable of accelerating ultra-high energy cosmic rays (UHECRs).
A. Chokshi +59 more
core +2 more sources
The Cosmic Origins Spectrograph and the Future of Ultraviolet Astronomy [PDF]
, 2009 I describe the capabilities of the Cosmic Origins Spectrograph, scheduled for May 2009 installation on the Hubble Space Telescope. With a factor-of-ten increase in far-UV throughput for moderate resolution spectroscopy, COS will enable a range of ...
George Sonneborn +4 more
core +1 more source
A 5G Beam Selection Machine Learning Algorithm for Unmanned Aerial Vehicle Applications
Wireless Communications and Mobile Computing, Volume 2020, Issue 1, 2020., 2020 The unmanned aerial vehicles (UAVs) emerged into a promising research trend within the recurrent year where current and future networks are to use enhanced connectivity in these digital immigrations in different fields like medical, communication, and search and rescue operations among others.
Hao Meng +4 more
wiley +1 more source
Long‐Range Scalar Forces in Five‐Dimensional General Relativity
Advances in Mathematical Physics, Volume 2020, Issue 1, 2020., 2020 We present new results regarding the long‐range scalar field that emerges from the classical Kaluza unification of general relativity and electromagnetism. The Kaluza framework reproduces known physics exactly when the scalar field goes to one, so we studied perturbations of the scalar field around unity, as is done for gravity in the Newtonian limit ...
L. L. Williams, Eugen Radu
wiley +1 more source
Antigravity, an Answer to Nature’s Phenomena including the Expansion of the Universe
Advances in High Energy Physics, Volume 2020, Issue 1, 2020., 2020 The gravitational attraction force being proportional to the mass has been experimentally shown for several hundred years now, but no gravitational repulsion has been identified within the accepted scientific reasoning. Here, we show that the gravitational repulsion force, similar to the gravitational attraction among particles has also been in ...
C. K. Gamini Piyadasa, Farook Rahaman
wiley +1 more source
, 2008 We investigate the delayed, secondary GeV-TeV emission of gamma-ray bursts and its potential to probe the nature of intergalactic magnetic fields. Geometrical effects are properly taken into account for the time delay between primary high energy photons ...
Bamba K. +7 more
core +1 more source
, 2011 Ultra-high cosmic rays (UHECRs) with energies >10^19 eV emitted at cosmological distances will be attenuated by cosmic microwave and infrared background radiation through photohadronic processes.
Cavallo +20 more
core +1 more source
The Radiative Feedback of the First Cosmological Objects
, 1999 In hierarchical models of structure formation, an early cosmic UV background (UVB) is produced by the small (T_vir < 10^4 K) halos that collapse before reionization. The UVB at energies below 13.6eV suppresses the formation of stars or black holes inside
Abgrall H. +4 more
core +1 more source
Computer Simulations of Cosmic Reionization
, 2009 The cosmic reionization of hydrogen was the last major phase transition in the evolution of the universe, which drastically changed the ionization and thermal conditions in the cosmic gas.
Gnedin, Nickolay Y., Trac, Hy
core +1 more source