We demonstrate a non-inflationary solution to the cosmological horizon problem in scenarios in which our observable universe is confined to three spatial dimensions (a three-brane) embedded in a higher dimensional space. A signal traveling along an extra-dimensional null geodesic may leave our three-brane, travel into the extra dimensions, and subsequently return to a different place on our three-brane in a shorter time than the time a signal confined to our three-brane would take. Hence, these geodesics may connect distant points which would otherwise be ``outside'' the four dimensional horizon (points not in causal contact with one another).
Physical Review D
- Pub Date:
- September 2000
- Particle-theory and field-theory models of the early Universe;
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory
- 9 pages, 2 figures