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Session 13 - Large Scale Structure & Cosmology.
Display session, Monday, January 13
Metropolitan Ballroom,

[13.09] Quantum Uncertainty and Constraints on Dark Matter

G. W. Collins II (CWRU)

Since Robert Dicke pointed out the approximate equality bewteen the gravitational binding and expansion energies at the current era implied a remarkably fine tuned balance for the young universe, an exact balance between the two has risen to the status of dogma. The traditional form of the arguement (known as the Flatness Problem) is usually characterized by the current ratio (omega) between the matter density and that required to asymptotically stop the expansion of the universe. The current observed constraint that 10 > omega > 0.1 suggests that at the Planck time the agreement with unity must have been about 1 part in 10**59. This has been taken to mean that the close agreement with unity is in reality perfect in which case it is still perfect. However, this also implies that any tiny departure of omega from unity as an initial condition will lead to significant departures in the present era. Since an initial condition can only be applied at the beginning of an event, we consider the quantum uncertainty in omega at the Planck time and find it to be of the order of the Planck mass divided by the mass of the universe used to determine omega. This implied an uncertainty in the initial value of omega of about 1 part in 10**59. However, this tiny uncertainty will be amplified by fifty nine powers of ten due to the expansion of the universe. This suggests we should find a current uncertainty in omega of about its own value. Thus, demanding greatest perfection in the initial conditions governing the dynamical expansion of the universe taht is allowed by the quantum nature of the universe leads to a value of omega that is in full agreement with observation.

Program listing for Monday