Formal Definition
Hyperbolic n-space, denoted Hn, is the maximally symmetric, simply connected, n-dimensional Riemannian manifold with constant sectional curvature −1. Hyperbolic space is the principal example of a space exhibiting hyperbolic geometry. It can be thought of as the negative-curvature analogue of the n-sphere. Although hyperbolic space Hn is diffeomorphic to Rn its negative-curvature metric gives it very different geometric properties.
Hyperbolic 2-space, H², is also called the hyperbolic plane.
Read more about this topic: Hyperbolic Space
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