# Liouville surface

From Encyclopedia of Mathematics

2020 Mathematics Subject Classification: *Primary:* 53A05 [MSN][ZBL]

A surface for which the equations of the geodesics admit a quadratic integral $a_{ij} du^i du^j$, where the tensor $a_{ij}$ is distinct from the metric tensor $g_{ij}$ of the surface. For example, a surface of constant Gaussian curvature is a Liouville surface. For a surface to admit a geodesic mapping onto a plane it is necessary and sufficient that it be a Liouville surface (Dini's theorem). See also Liouville net.

#### References

[a1] | W. Blaschke, K. Leichtweiss, "Elementare Differentialgeometrie", Springer (1973) |

[a2] | M. Berger, B. Gostiaux, "Differential geometry: manifolds, curves, and surfaces", Springer (1988) (Translated from French) |

**How to Cite This Entry:**

Liouville surface.

*Encyclopedia of Mathematics.*URL: http://encyclopediaofmath.org/index.php?title=Liouville_surface&oldid=53747

This article was adapted from an original article by I.Kh. Sabitov (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article