The Accelerating Universe, Dark Energy, and Einstein's Enigma
نویسنده
چکیده
The Original Cosmological Constant As we have seen, in 1917 Einstein boldly launched modern cosmology by applying general relativity to the entire universe. He disposed of the Newtonian problem at infinity by invoking a closed geometry.[2] For his model to be consistent with contemporary astronomical data that suggested a static universe, Einstein reluctantly introduced an extra term that opposed gravity, a “cosmological constant” Λ > 0. It had to be small because its presence was not needed at galactic and smaller scales; in SI units, Λobs ≤ 10 -35 s-2.[7] To oppose gravity it exerts negative pressure,
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