Foliations of Manifolds |
In General
* Idea: A p-dimensional foliation
of an n-dimensional manifold M is a decomposition of M as a union
of parallel submanifolds (leaves) of dimension p.
* Leaves: Each leaf in a foliation is
an embedded submanifold of dimension p.
* Result: Every complete 2-manifold can occur
as the leaf of a foliation of a compact 3-manifold, but not every complete 3-manifold can occur
as the leaf of a foliation of a 4D one!
> Related topics:
see embeddings and immersions;
extrinsic curvature [and extremal surfaces];
gauge transformations; Hypersurface;
metric decomposition.
> Special cases:
see 3D manifolds; FLRW spacetime.
> Online resources:
see Wikipedia page.
Foliations of Riemannian Manifolds
* Singular Riemannian foliation: A singular
foliation is called a singular Riemannian foliation if every geodesic that is perpendicular
to one leaf is perpendicular to every leaf it meets; A typical example is the partition of
a complete Riemannian manifold into orbits of an isometric action.
@ Singular Riemannian foliation:
Alexandrino et al DG&A(13) [intro].
Foliations of Lorentzian Manifolds
> s.a. initial-value formulation of general relativity.
* Spacelike case: A spacetime foliation
follows from (but is weaker than) a choice of time or gauge in an initial-value formulation;
Every foliation gives a curve in the space of Riemannian geometries (+ a lapse function + a
shift vector); The choice of an appropriate foliation is important in numerical relativity.
@ Spacelike and timelike foliations of spacetime: in Lau CQG(96)gq/95;
Walschap JGP(99) [spacelike, properties];
Harris & Low CQG(01)gq [shape of space];
Husain et al PRD(02)gq/01 [spherical, spatially flat];
Bolós GRG(07)gq/05 [stability between foliations].
@ Special spacelike foliations: Delphenich gq/02 [proper time foliations];
Sánchez & Senovilla CQG(07)-a0709 [with respect to a static Killing vector, uniqueness].
@ Lightlike foliations: Bolós MPCPS(05)gq.
@ Constant mean curvature: Christodoulou & Francaviglia GRG(79) [Einstein spacetimes admitting a Gaussian foliation];
Andersson et al JGP(97)gq/96 [2+1 globally hyperbolic];
Rendall HPA(96)gq [conjectures],
CMP(97)gq/96 [with 2 Killing vector fields],
gq/96-proc [results];
Andersson & Iriondo gq/97;
Isenberg & Rendall CQG(98)gq/97 [counterexamples];
Gowdy gq/01 [Minkowski and Schwarzschild spacetimes];
Malec & Ó Murchadha PRD(03)gq,
gq/03,
PRD(09)-a0903 [Schwarzschild spacetime];
Klainerman & Rodnianski a0801 [breakdown];
Martín-Moruno AIP(12)-a1201 [in our region of spacetime];
Gerhardt a1902
[spacetimes asymptotic to open FLRW spacetimes].
@ Other types: Berger et al AP(97)gq [T2 isometry];
Henkel AIP(02)gq/01,
JMP(02)gq/01,
JMP(02)gq/01 [with prescribed mean curvature];
Müller a0904/TAMS [globally hyperbolic manifolds, nice foliations];
García JMP(13)-a1212 [conformally flat leaves].
@ And singularities: Alcubierre CQG(03) [focusing singularities and gauge shocks].
Related Topic: Webs
* Web:
A family of foliations of a manifold in general positions.
* Orthogonal web:
In an n-dimensional manifold with metric, a set of n pairwise
transversal and orthogonal foliations of connected submanifolds of codimension 1.
@ Web: Chern BAMS(82) [geometry];
Zakharevich mp/00 [Veronese webs];
Grifone & Salem ed-01;
Fleischhack MN(04)mp/03 [parallel transport],
CMP(04) [degenerate webs].
> Online resources:
see Wikipedia page.
References
@ General: Reinhart 83;
Bejancu & Farran 06 [and geometric structures].
@ 3D manifolds:
Shields T&A(06) [equivalence classes of foliations];
Calegari 07.
@ Manifolds that can / cannot be leaves of foliations:
Cantwell & Conlon Top(87) [every surface is a leaf];
Attie & Hurder Top(96) [manifolds that cannot].
main page
– abbreviations
– journals – comments
– other sites – acknowledgements
send feedback and suggestions to bombelli at olemiss.edu – modified 12 feb 2019