Fixed point theorem for a strictly distance-decreasing map on a compact metric space

ID: fixed-point-theorem-for-a-strictly-distance-decreasing-map-on-a-compact-metric-space

Let be a nonempty compact metric space and let satisfy whenever . Then has exactly one fixed point. The distance condition implies continuity, and attains a minimum by compactness. If a minimizer were not a fixed point, then would contradict minimality. Two distinct fixed points would contradict the same strict distance inequality directly. A uniform Lipschitz constant below is unnecessary; compactness replaces the quantitative hypothesis of the contraction mapping theorem.

New to topics? Read the docs here!