Abstract
We calculate the power spectrum of metric fluctuations in inflationary cosmology starting with initial conditions which are imposed mode by mode when the wavelength equals some critical length corresponding to a new energy scale at which trans-Planckian physics becomes important. In this case, the power spectrum can differ from what is calculated in the usual framework (which amounts to choosing the adiabatic vacuum state). The fractional difference in the results depends on the ratio between the Hubble expansion rate during inflation and the new energy scale We show how and why different choices of the initial vacuum state (stemming from different assumptions about trans-Planckian physics) lead to fractional differences which depend on different powers of As we emphasize, the power in general also depends on whether one is calculating the power spectrum of density fluctuations or of gravitational waves.
- Received 19 May 2003
DOI:https://doi.org/10.1103/PhysRevD.68.063513
©2003 American Physical Society