Abstract
Title: "Conformal Symmetry and the Cosmological Term"
Abstract:
The de Sitter and anti-de Sitter spacetimes are transitive under a
mixture of translations and proper conformal transformations. The relative
importance of each one of these transformations is determined by the value
of the cosmological constant $\Lambda$. For a vanishing $\Lambda$, both de
Sitter groups are reduced to the Poincar\'e group, and both de Sitter spaces
become the Minkowski spacetime, which is transitive under ordinary
translations. For an infinite cosmological constant, the resulting spacetime
is a singular, four-dimensional cone-space, transitive under {\it proper}
conformal transformations. The geometric properties of this cone-space are
studied, and its possible relation with the initial conditions of a big bang
universe discussed.