Dark Matter in the Universe

Dark Matter in the Universe

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Physics and astrophysics came to dark matter through many different routes, finally accepting it, but often with some distaste. It has been noticed that the existence of dark matter is yet another displacement of humans from the centre of the Universe: not only do our planet and our sun have no central position in the Universe, not only are humans just animals (although with a 'specialized' central nervous system), but even the material of which we are made is only a marginal component of the cosmic substance! If this is the right attitude to take, scientists feeling distaste for dark matter are much like Galileo Galilei's colleagues who refused to look through the telescope to watch the Medici planets. Nevertheless, astronomers, when required to take a ballot in favour of some cosmological model, often still vote for 'pure baryonic' with substantial majorities, although most cosmologists assume that a 'cold' component of dark matter plays a role in producing the world as we observe it. Among the many subjects covered by the book, particular emphasis was given to 1) summarizing the current status of the observations both of the distribution of the nearby galaxies and of the evolution of more distant galaxies; 2) advanced statistical techniques for quantifying structure in galaxy redshift and peculiar velocity surveys; 3) the art of cosmic inflation and models for dark matter candidates, and their implications for cosmic microwave background observations; 4) implications of cold dark matter variants for large scale structure, as worked out both by quasi-linear techniques and by fully nonlinear simulations; and 5) Eulerian and Lagrangian approximations for treating the nonlinear dynamics.In turn, the global galactic dynamics controls the formation of cold gas clouds (in our galaxy molecular clouds) inside of which stars are produced. ... For primordial abundances, instability occurs (assuming pressure equilibrium) if the gas cools below Tgals I 105 K. The ... Now, if the heat gain due to conductivity is greater than the loss due to radiation, the cloud will not survive, but clouds larger than aanbsp;...

Title:Dark Matter in the Universe
Author:Società italiana di fisica
Publisher:IOS Press - 1997-01-01


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