منابع مشابه
Time Delays in Cosmic Ray Propagation
Cosmic Rays (CR) travel at speeds essentially indistinguishable from the speed of light. However whilst travelling through magnetic fields, both regular and turbulent, they are delayed behind the light since they are usually charged particles and their paths are not linear. Those delays can be so long that they are an impediment to correctly identifying sources which may be variable in time. Fu...
متن کاملConstraints on the Cosmic Infra - Red Background based on BeppoSAX and CAT spectra of Mkn 501
The TeV and X-ray data obtained by the imaging Cherenkov telescope CAT and X-ray satellite BeppoSAX during the remarkable flare of Mkn 501 in April 16, 1997 are used to constrain the flux of the Cosmic Infrared Background (CIB) using different CIB models. We show that a non-negligible absorption of γ-rays due to the CIB could take place already in the low-energy (sub-TeV) domain of the spectrum...
متن کاملConstraints on the cosmic infra - red background based on BeppoSAX and CAT spectra of Markarian 501
The TeV and X-ray data obtained by the imaging Cherenkov telescope CAT and X-ray satellite BeppoSAX during the remarkable flare of Mkn 501 in April 16, 1997 are used to constrain the flux of the Cosmic Infrared Background (CIB) using different CIB models. We show that a non-negligible absorption of γ-rays due to the CIB could take place already in the low-energy (sub-TeV) domain of the spectrum...
متن کاملCosmic clocks, cosmic variance and cosmic averages
Cosmic acceleration is explained quantitatively, purely in general relativity with matter obeying the strong energy condition, as an apparent effect due to quasilocal gravitational energy differences that arise in the decoupling of bound systems from the global expansion of the universe. “Dark energy” is recognised as a misidentification of those aspects of gravitational energy which by virtue ...
متن کاملCat$^1$-polygroups and pullback cat$^1$-polygroups
In this paper, we give the notions of crossed polymodule and cat$^1$-polygroup as a generalization of Loday's definition. Then, we define the pullback cat$^1$-polygroup and we obtain some results in this respect. Specially, we prove that by a pullback cat$^1$-polygroup we can obtain a cat$^1$-group.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Science
سال: 1996
ISSN: 0036-8075,1095-9203
DOI: 10.1126/science.274.5286.324i