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in subjects: "Radiations 640106* -- Astrophysics & Cosmology-- Cosmology"  
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Black holes, pregalactic stars, and the dark matter problem

Description: We review the different ways in which black holes might form and discuss their various astrophysical and cosmological consequences. We then consider the various constraints on the form of the dark matter and conclude that black holes could have a significant cosmological density only if they are of primordial origin or remnants of a population of pregalactic stars. This leads us to discuss the other cosmological effects of primordial black holes and pregalactic stars. 239 refs., 7 figs., 5 tabs. more
Date: June 1, 1985
Creator: Carr, B.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The large scale microwave background anisotropy in decaying particle cosmology

Description: We investigate the large-scale anisotropy of the microwave background radiation in cosmological models with decaying particles. The observed value of the quadrupole moment combined with other constraints gives an upper limit on the redshift of the decay z/sub d/ < 3-5. 12 refs., 2 figs.
Date: June 1, 1987
Creator: Panek, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Measurement of the large-scale anisotropy of the cosmic background radiation at 3mm

Description: A balloon-borne differential radiometer has measured the large-scale anisotropy of the cosmic background radiation (CBR) with high sensitivity. The antenna temperature dipole anistropy at 90 GHz (3 mm wavelength) is 2.82 +- 0.19 mK, corresponding to a thermodynamic anistropy of 3.48 +- mK for a 2.7 K blackbody CBR. The dipole direction, 11.3 +- 0.1 hours right ascension and -5.7/sup 0/ +- 1.8/sup 0/ declination, agrees well with measurements at other frequencies. Calibration error dominates mag… more
Date: December 1, 1983
Creator: Epstein, G.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Chaotic inflation and the omega problem

Description: One of the most compelling features of inflationary cosmology is that it provides a solution to the flatness problem, i.e. an explanation of the fact that the ratio, {Omega}, of the present mass density to the closure density is so close to unity. Indeed, inflationary models naturally lead to a present value of the closure parameter which is equal to unity to many significant figures. At the same time, however, there are at least some observational indications that the present value of the clos… more
Date: December 1, 1990
Creator: Mathews, G. J.; Graziani, F. & Kurki-Suonio, H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Astrophysical cosmology

Description: The last several years have seen a tremendous ferment of activity in astrophysical cosmology. Much of the theoretical impetus has come from particle physics theories of the early universe and candidates for dark matter, but what promise to be even more significant are improved direct observations of high z galaxies and intergalactic matter, deeper and more comprehensive redshift surveys, and the increasing power of computer simulations of the dynamical evolution of large scale structure. Upper … more
Date: January 1, 1986
Creator: Bardeen, J.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Evidence for observation of underground muons from Cygnus X-3

Description: We have observed evidence for an average underground muon flux of approx. = 7 x 10/sup -11/ cm/sup -2/ s/sup -1/ which points back to the x-ray binary Cygnus X-3 and which exhibits the 4.8 h periodicity observed for other radiation from this source. These observations cannot be explained by conventional models of the propagation and interaction of cosmic rays. 13 refs., 2 figs.
Date: January 1, 1985
Creator: Bartelt, J.; Courant, H.; Heller, K.; Heppelmann, S.; Joyce, T.; Peterson, E. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The Large-Scale Peculiar Velocity Field in Flat Models of the Universe

Description: The inflationary Universe scenario predicts a flat Universe and both adiabatic and isocurvature primordial density perturbations with the Zel'dovich spectrum. The two simplest realizations, models dominated by hot or cold dark matter, seem to be in conflict with observations. Flat models are examined with two components of mass density, where one of the components of mass density is smoothly distributed and the large-scale (greater than or equal to10h/sup -1/ MpC) peculiar velocity field for th… more
Date: October 1, 1986
Creator: Vittorio, N. & Turner, M. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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