The mathematical object which controls the rate of geodesic deviation.
Sectional Curvature
See also
Bishop's Inequality, Cheeger's Finiteness Theorem, GeodesicExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Sectional Curvature." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/SectionalCurvature.html