Riemannian geometry, or elliptic geometry (math.)

• MICROPAEDIA
• MACROPAEDIA
• major ref. in Geometry [Ref 1], [Ref 2]
• application in relativity theory
• gravitation
• Riemann's research [Ref 1]; [Ref 2]
• for lists of related subjects see PROPAEDIA: Sections 10/21; 10/22