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Galaxy Formation
•Lots of theory here!
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•Jeans (1902), gravitational collapse in a stationary medium, depends on sound speed and density
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•Lifshitz (1946), general case including expanding medium, but collapse is not typically exponetial and structures grow very slowly – too slowly! Cannot start with infinitesimal perturbations.
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•Zeldovich, Novikov, Peebles (1960s) used finite perturbations (1 part in 10000).
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•Main test of all this is the cosmic microwave background radiation, since fluctations should leave imprints.
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