# Physics Notes by Jakob Schwichtenberg

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quantum_gravity:concepts:metric

# The Metric

In quantum field theory (in its present imperfect form) the Minkowski metric is the vacuum expectation value of the Riemannian metric. It seems unsafe to restrict the attention arbitrarily to the special case of vanishing cosmological constant, for this ease is unstable to deformations; a nonzero cosmological constant may, for example, appear spontaneously through renormalization. In that case the zeroth approximation (or vacuum expectation value) of the metric cannot be Minkowski, but must be de Sitter. Our previous analysis must therefore be modified by the substitution of the de Sitter group for the Poincare group” from Massless particles, conformal group, and de Sitter Universe by E. Angelopoulos

quantum_gravity/concepts/metric.txt · Last modified: 2017/12/06 09:33 (external edit)