The Riemann curvature tensor is a tensor that measures the curvature of a surface at a given point. It is a fundamental object in Riemannian geometry and is used to study the geometry of curved surfaces.

The Riemann curvature tensor is the derivative of the Christoffel symbols. This relationship is known as the Gauss-Codazzi equation.

The Gauss equation relates the Riemann curvature tensor to the sectional curvature. It is a fundamental equation in Riemannian geometry and is used to study the geometry of curved surfaces.

The Gauss-Bonnet theorem relates the total curvature of a closed surface to its genus. It is a fundamental theorem in Riemannian geometry and is used to study the geometry of closed surfaces.

Hyperbolic space is a space that is locally Euclidean but globally non-Euclidean. It is a fundamental example of a Riemannian manifold and is used to study the geometry of curved surfaces.

Euclidean space is a space that is locally Euclidean and globally Euclidean. It is the most familiar example of a Riemannian manifold and is used to study the geometry of flat surfaces.

Elliptic space is a space that is locally Euclidean but globally non-compact. It is a fundamental example of a Riemannian manifold and is used to study the geometry of curved surfaces.

Riemannian space is a space that is locally Euclidean and globally compact. It is a fundamental example of a Riemannian manifold and is used to study the geometry of curved surfaces.

The Cartan-Hadamard theorem states that a Riemannian manifold is complete if and only if its sectional curvature is non-negative. It is a fundamental theorem in Riemannian geometry and is used to study the geometry of Riemannian manifolds.

The Poincaré duality theorem states that a Riemannian manifold is simply connected if and only if its fundamental group is trivial. It is a fundamental theorem in Riemannian geometry and is used to study the topology of Riemannian manifolds.

The Gauss-Bonnet theorem states that a Riemannian manifold is orientable if and only if its Euler characteristic is zero. It is a fundamental theorem in Riemannian geometry and is used to study the topology of Riemannian manifolds.

The Bishop-Gromov theorem states that a Riemannian manifold is compact if and only if its volume is finite. It is a fundamental theorem in Riemannian geometry and is used to study the geometry of Riemannian manifolds.

The Myers-Steenrod theorem states that a Riemannian manifold is flat if and only if its curvature tensor is zero. It is a fundamental theorem in Riemannian geometry and is used to study the geometry of Riemannian manifolds.

Einstein's theorem states that a Riemannian manifold is Einstein if and only if its Ricci curvature is proportional to its metric. It is a fundamental theorem in Riemannian geometry and is used to study the geometry of Einstein manifolds.

Kähler's theorem states that a Riemannian manifold is Kähler if and only if its Kähler form is closed. It is a fundamental theorem in Riemannian geometry and is used to study the geometry of Kähler manifolds.