For a 4-dimensional spatially flat Friedmann-Robertson-Walker universe with a scalar field φ(x), potential V(φ) and constant equation of state w=p/p, we show that an expanding solution characterized by Ε=3(1 + w)/2 produces the same scalar perturbations as a contracting solution with Ε̂=1/Ε. The same symmetry applies to both the dominant and subdominant scalar perturbation modes. This result admits a simple physical interpretation and generalizes to d spacetime dimensions if we define Ε=[(2d-5) + (d-1)w]/(d-2).
|Original language||English (US)|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - Jul 2004|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)