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Injectivity Domain


The injectivity domain at a point x of a complete Riemannian manifold is the set of tangent vectors that reach a point before the cut time along their geodesic. In terms of the exponential map, the open injectivity domain is

 I(x)={p in T_xM:d(x,exp_x(ap))=a||p|| for some a>1}.

Its closure includes minimizing vectors at the cut time. The domain is star-shaped about zero, but need not be convex for an arbitrary metric.


See also

Exponential Map, Geodesic, Ma-Trudinger-Wang Condition, Riemannian Metric, Tangent Space

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References

Figalli, A.; Gallouët, T. O.; and Rifford, L. "On the Convexity of Injectivity Domains on Nonfocal Manifolds." SIAM J. Math. Anal. 47, 969-1000, 2015. https://doi.org/10.1137/140961821.

Cite this as:

Weisstein, Eric W. "Injectivity Domain." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/InjectivityDomain.html

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