First variation of area formula

First variation of area formula

In Riemannian geometry, the first variation of area formula relates the mean curvature of a hypersurface to the rate of change of its area as it evolves in the outward normal direction.

Let Sigma(t) be a smooth family of oriented hypersurfaces in a Riemannian manifold "M" such that the velocity of each point is given by the outward unit normal at that point. The first variation of area formula is

:frac{d}{dt}, dA = H ,dA,

where "dA" is the area form on Sigma(t) induced by the metric of "M", and "H" is the mean curvature of Sigma(t).

References

*Chow, Lu, and Ni, "Hamilton's Ricci Flow." AMS Science Press, GSM volume 77, 2006.


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Coarea formula — In the mathematical field of geometric measure theory, the coarea formula expresses the integral of a function over an open set in Euclidean space in terms of the integral of the level sets of another function. A special case is Fubini s theorem …   Wikipedia

  • List of mathematics articles (F) — NOTOC F F₄ F algebra F coalgebra F distribution F divergence Fσ set F space F test F theory F. and M. Riesz theorem F1 Score Faà di Bruno s formula Face (geometry) Face configuration Face diagonal Facet (mathematics) Facetting… …   Wikipedia

  • Semi-empirical mass formula — In nuclear physics, the semi empirical mass formula (SEMF), sometimes also called Weizsäcker s formula, is a formula used to approximate the mass and various other properties of an atomic nucleus. As the name suggests, it is partially based on… …   Wikipedia

  • Mean curvature — In mathematics, the mean curvature H of a surface S is an extrinsic measure of curvature that comes from differential geometry and that locally describes the curvature of an embedded surface in some ambient space such as Euclidean space. The… …   Wikipedia

  • Inverse mean curvature flow — In the field of differential geometry in mathematics, inverse mean curvature flow (IMCF) is an example of a geometric flow of hypersurfaces a Riemannian manifold (for example, smooth surfaces in 3 dimensional Euclidean space). Intuitively, a… …   Wikipedia

  • river — river1 riverless, adj. riverlike, adj. /riv euhr/, n. 1. a natural stream of water of fairly large size flowing in a definite course or channel or series of diverging and converging channels. 2. a similar stream of something other than water: a… …   Universalium

  • chemical compound — Introduction  any substance composed of identical molecules consisting of atoms (atom) of two or more chemical elements (chemical element).       All the matter in the universe is composed of the atoms of more than 100 different chemical elements …   Universalium

  • Archimedes — For other uses, see Archimedes (disambiguation). Archimedes of Syracuse (Greek: Ἀρχιμήδης) …   Wikipedia

  • San Francisco — This article is about the city and county in California. For other uses, see San Francisco (disambiguation). San Francisco   City and county   City and County of San Francisco …   Wikipedia

  • probability and statistics — ▪ mathematics Introduction       the branches of mathematics concerned with the laws governing random events, including the collection, analysis, interpretation, and display of numerical data. Probability has its origin in the study of gambling… …   Universalium

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”