Both sides previous revision Previous revision Next revision | Previous revision | ||
advanced_tools:bianchi_identities [2019/01/16 14:24] 129.13.36.189 [Concrete] |
advanced_tools:bianchi_identities [2019/01/16 14:35] (current) jakobadmin [Abstract] |
||
---|---|---|---|
Line 28: | Line 28: | ||
---- | ---- | ||
- | Bianchi identities express the fact that the boundary of a boundary is always zero. Mathematically this follows by applying Stoke's theorem twice. | + | Bianchi identities express the fact that the boundary of a boundary is always zero. Mathematically this follows by applying Stoke's theorem twice. This is discussed explicitly in the book No-Nonsense Electrodynamics by Schwichtenberg |
<tabbox Abstract> | <tabbox Abstract> | ||
- | + | In general relativity, the Bianchi identity | |
- | <note tip> | + | $$ \nabla R = \nabla \nabla \theta =0 $$ |
- | The motto in this section is: //the higher the level of abstraction, the better//. | + | roughly says "that the sum over a closed two-dimensional surface of rotations induced by Riemannian curvature is equal to zero. [...] Geometrically this means that the density of the moment of rotation induced by Riemannian curvature is equal to zero automatically." ([[https://link.springer.com/article/10.1007%2FBF01882731|Source]]) |
- | </note> | + | |
<tabbox Why is it interesting?> | <tabbox Why is it interesting?> | ||
<blockquote> | <blockquote> |