Alexandrov space
In
geodesic triangles in the space to geodesic triangles in standard constant-curvature Riemannian surfaces.[1][2]
One can show that the Hausdorff dimension of an Alexandrov space with curvature ≥ k is either a non-negative integer or infinite.[1] One can define a notion of "angle" and "tangent cone" in these spaces.
Alexandrov spaces with curvature ≥ k are important as they form the limits (in the
Gromov-Hausdorff metric) of sequences of Riemannian manifolds with sectional curvature ≥ k,[3] as described by Gromov's compactness theorem
.
Alexandrov spaces with curvature ≥ k were introduced by the Russian mathematician
.