A thermometer for registering the temperature and a water gauge are placed in the manifold.
Π ΠΊΠΎΠ»Π»Π΅ΠΊΡΠΎΡΠ΅ ΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½Ρ ΡΠ΅ΡΠΌΠΎΠΌΠ΅ΡΡ Π΄Π»Ρ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΡ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ ΠΈ ΡΠΊΠ°Π·Π°ΡΠ΅Π»Ρ ΡΡΠΎΠ²Π½Ρ Π²ΠΎΠ΄Ρ.
We may define a continuous manifold as any continuum of elements, such that a single element is defined by n continuously variable magnitudes.
ΠΡ ΠΌΠΎΠΆΠ΅ΠΌ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΠΈΡΡ Π½Π΅ΠΏΡΠ΅ΡΡΠ²Π½ΠΎΠ΅ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠ΅ ΠΊΠ°ΠΊ Π»ΡΠ±ΡΡ Π½Π΅ΠΏΡΠ΅ΡΡΠ²Π½ΡΡ ΡΠΎΠ²ΠΎΠΊΡΠΏΠ½ΠΎΡΡΡ ΡΠ»Π΅ΠΌΠ΅Π½ΡΠΎΠ², Π² ΠΊΠΎΡΠΎΡΠΎΠΉ ΠΎΡΠ΄Π΅Π»ΡΠ½ΡΠΉ ΡΠ»Π΅ΠΌΠ΅Π½Ρ Π·Π°Π΄Π°ΡΡΡΡ n Π½Π΅ΠΏΡΠ΅ΡΡΠ²Π½ΠΎ ΠΈΠ·ΠΌΠ΅Π½ΡΡΡΠΈΠΌΠΈΡΡ Π²Π΅Π»ΠΈΡΠΈΠ½Π°ΠΌΠΈ.
We have instances of manifolds, but not instances of Euclidean space.
Π£ Π½Π°Ρ Π΅ΡΡΡ ΠΏΡΠΈΠΌΠ΅ΡΡ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠΉ, Π½ΠΎ Π½Π΅Ρ ΠΏΡΠΈΠΌΠ΅ΡΠΎΠ² Π΅Π²ΠΊΠ»ΠΈΠ΄ΠΎΠ²Π° ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π°.
By means of the proper webs, brackets and bosses, the crankcase would also carry the crankshaft, the rocker arms and bearings, and the intake manifold.
Π‘ ΠΏΠΎΠΌΠΎΡΡΡ ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΡΡΡΠΈΡ ΠΏΠ΅ΡΠ΅ΠΌΡΡΠ΅ΠΊ, ΠΊΡΠΎΠ½ΡΡΠ΅ΠΉΠ½ΠΎΠ² ΠΈ Π±ΠΎΠ±ΡΡΠ΅ΠΊ ΠΊΠ°ΡΡΠ΅Ρ Π΄ΠΎΠ»ΠΆΠ΅Π½ Π±ΡΠ» ΡΠ°ΠΊΠΆΠ΅ Π½Π΅ΡΡΠΈ ΠΊΠΎΠ»Π΅Π½ΡΠ°ΡΡΠΉ Π²Π°Π», ΠΊΠΎΡΠΎΠΌΡΡΠ»Π° ΠΈ ΠΏΠΎΠ΄ΡΠΈΠΏΠ½ΠΈΠΊΠΈ, Π° ΡΠ°ΠΊΠΆΠ΅ Π²ΠΏΡΡΠΊΠ½ΠΎΠΉ ΠΊΠΎΠ»Π»Π΅ΠΊΡΠΎΡ.
Time produces a ripple in the representational manifold that travels out into spacetime in different directions and at different velocities.
ΠΡΠ΅ΠΌΡ Π²ΡΠ·ΡΠ²Π°Π΅Ρ ΡΡΠ±Ρ Π² ΡΠ΅ΠΏΡΠ΅Π·Π΅Π½ΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΌ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠΈ, ΡΠ°ΡΠΏΡΠΎΡΡΡΠ°Π½ΡΡΡΡΡΡΡ Π² ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π΅-Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ Π² ΡΠ°Π·Π½ΡΡ Π½Π°ΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡΡ ΠΈ Ρ ΡΠ°Π·Π½ΡΠΌΠΈ ΡΠΊΠΎΡΠΎΡΡΡΠΌΠΈ.
There may still be βdelocalizedβ states that live on the whole spatial manifold.
ΠΡΠΈ ΡΡΠΎΠΌ ΠΌΠΎΠ³ΡΡ ΡΡΡΠ΅ΡΡΠ²ΠΎΠ²Π°ΡΡ Β«Π΄Π΅Π»ΠΎΠΊΠ°Π»ΠΈΠ·ΠΎΠ²Π°Π½Π½ΡΠ΅Β» ΡΠΎΡΡΠΎΡΠ½ΠΈΡ, ΠΎΡ Π²Π°ΡΡΠ²Π°ΡΡΠΈΠ΅ Π²ΡΡ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π΅Π½Π½ΠΎΠ΅ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠ΅.
There are many KΓ€hler manifolds which are of the form G/H where H is a subgroup of a compact Lie group G.
Π‘ΡΡΠ΅ΡΡΠ²ΡΠ΅Ρ ΠΌΠ½ΠΎΠ³ΠΎ ΠΊΡΠ»Π΅ΡΠΎΠ²ΡΡ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠΉ Π²ΠΈΠ΄Π° G/H, Π³Π΄Π΅ H β ΠΏΠΎΠ΄Π³ΡΡΠΏΠΏΠ° ΠΊΠΎΠΌΠΏΠ°ΠΊΡΠ½ΠΎΠΉ Π³ΡΡΠΏΠΏΡ ΠΠΈ G.
Develop an analogous theory for graphs instead of manifolds.
Π Π°Π·ΡΠ°Π±ΠΎΡΠ°ΠΉΡΠ΅ Π°Π½Π°Π»ΠΎΠ³ΠΈΡΠ½ΡΡ ΡΠ΅ΠΎΡΠΈΡ Π΄Π»Ρ Π³ΡΠ°ΡΠΎΠ² Π²ΠΌΠ΅ΡΡΠΎ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠΉ.
Two manifolds M 1 and M 2 are called commensurable if they admit a common finite covering.
ΠΠ²Π° ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΡ M 1 ΠΈ M 2 Π½Π°Π·ΡΠ²Π°ΡΡΡΡ ΡΠΎΠΈΠ·ΠΌΠ΅ΡΠΈΠΌΡΠΌΠΈ, Π΅ΡΠ»ΠΈ ΠΎΠ½ΠΈ Π΄ΠΎΠΏΡΡΠΊΠ°ΡΡ ΠΎΠ±ΡΠ΅Π΅ ΠΊΠΎΠ½Π΅ΡΠ½ΠΎΠ»ΠΈΡΡΠ½ΠΎΠ΅ Π½Π°ΠΊΡΡΡΠΈΠ΅.
Let M = (M, g) denote a connected closed oriented smooth Riemannian manifold with Riemannian metric g.
ΠΡΡΡΡ M = (M, g) β ΡΠ²ΡΠ·Π½ΠΎΠ΅ Π·Π°ΠΌΠΊΠ½ΡΡΠΎΠ΅ ΠΎΡΠΈΠ΅Π½ΡΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ΅ Π³Π»Π°Π΄ΠΊΠΎΠ΅ ΡΠΈΠΌΠ°Π½ΠΎΠ²ΠΎ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠ΅ Ρ ΡΠΈΠΌΠ°Π½ΠΎΠ²ΠΎΠΉ ΠΌΠ΅ΡΡΠΈΠΊΠΎΠΉ g.
Usually manifolds are locally described by coordinate charts.
ΠΠ±ΡΡΠ½ΠΎ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΡ Π»ΠΎΠΊΠ°Π»ΡΠ½ΠΎ ΠΎΠΏΠΈΡΡΠ²Π°ΡΡΡΡ ΠΊΠΎΠΎΡΠ΄ΠΈΠ½Π°ΡΠ½ΡΠΌΠΈ ΠΊΠ°ΡΡΠ°ΠΌΠΈ.
Well, a smooth manifold locally has the same qualitative structure everywhere, regardless of whether we actually find data points in some specific small region or not.
ΠΡΠ°ΠΊ, Π³Π»Π°Π΄ΠΊΠΎΠ΅ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠ΅ Π»ΠΎΠΊΠ°Π»ΡΠ½ΠΎ ΠΏΠΎΠ²ΡΡΠ΄Ρ ΠΈΠΌΠ΅Π΅Ρ ΠΎΠ΄Π½Ρ ΠΈ ΡΡ ΠΆΠ΅ ΠΊΠ°ΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΡ ΡΡΡΡΠΊΡΡΡΡ Π½Π΅Π·Π°Π²ΠΈΡΠΈΠΌΠΎ ΠΎΡ ΡΠΎΠ³ΠΎ, Π½Π°Ρ ΠΎΠ΄ΠΈΠΌ Π»ΠΈ ΠΌΡ ΡΠΎΡΠΊΠΈ Π΄Π°Π½Π½ΡΡ Π² ΠΊΠ°ΠΊΠΎΠΉ-Π»ΠΈΠ±ΠΎ ΠΊΠΎΠ½ΠΊΡΠ΅ΡΠ½ΠΎΠΉ ΠΌΠ°Π»ΠΎΠΉ ΠΎΠ±Π»Π°ΡΡΠΈ.
In order to define a Riemannian metric, we first need the concept of a differentiable manifold.
Π§ΡΠΎΠ±Ρ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΠΈΡΡ ΡΠΈΠΌΠ°Π½ΠΎΠ²Ρ ΠΌΠ΅ΡΡΠΈΠΊΡ, Π½Π°ΠΌ ΡΠ½Π°ΡΠ°Π»Π° ΠΏΠΎΠ½Π°Π΄ΠΎΠ±ΠΈΡΡΡ ΠΏΠΎΠ½ΡΡΠΈΠ΅ Π΄ΠΈΡΡΠ΅ΡΠ΅Π½ΡΠΈΡΡΠ΅ΠΌΠΎΠ³ΠΎ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΡ.
Notions like differentiability are not defined directly on the manifold, but emerge indirectly from compatibility conditions between different coordinate charts.
Π’Π°ΠΊΠΈΠ΅ ΠΏΠΎΠ½ΡΡΠΈΡ, ΠΊΠ°ΠΊ Π΄ΠΈΡΡΠ΅ΡΠ΅Π½ΡΠΈΡΡΠ΅ΠΌΠΎΡΡΡ, Π½Π΅ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΡΡΡΡ Π½Π΅ΠΏΠΎΡΡΠ΅Π΄ΡΡΠ²Π΅Π½Π½ΠΎ Π½Π° ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠΈ, Π° Π²ΠΎΠ·Π½ΠΈΠΊΠ°ΡΡ ΠΊΠΎΡΠ²Π΅Π½Π½ΠΎ ΠΈΠ· ΡΡΠ»ΠΎΠ²ΠΈΠΉ ΡΠΎΠ²ΠΌΠ΅ΡΡΠΈΠΌΠΎΡΡΠΈ ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ ΠΊΠΎΠΎΡΠ΄ΠΈΠ½Π°ΡΠ½ΡΡ ΠΊΠ°ΡΡ.
A differentiable submanifold is a differentiable manifold in its own right.
ΠΠΈΡΡΠ΅ΡΠ΅Π½ΡΠΈΡΡΠ΅ΠΌΠΎΠ΅ ΠΏΠΎΠ΄ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠ΅ ΡΠ°ΠΌΠΎ ΠΏΠΎ ΡΠ΅Π±Π΅ ΡΠ²Π»ΡΠ΅ΡΡΡ Π΄ΠΈΡΡΠ΅ΡΠ΅Π½ΡΠΈΡΡΠ΅ΠΌΡΠΌ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠ΅ΠΌ.
The model Riemannian manifold is Euclidean space itself.
ΠΠ±ΡΠ°Π·ΡΠΎΠΌ ΡΠΈΠΌΠ°Π½ΠΎΠ²Π° ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΡ ΡΠ»ΡΠΆΠΈΡ ΡΠ°ΠΌΠΎ Π΅Π²ΠΊΠ»ΠΈΠ΄ΠΎΠ²ΠΎ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²ΠΎ.
For example, compact Riemannian manifolds such as the sphere or torus cannot be diffeomorphic to Euclidean space due to their non-trivial topology.
ΠΠ°ΠΏΡΠΈΠΌΠ΅Ρ, ΠΊΠΎΠΌΠΏΠ°ΠΊΡΠ½ΡΠ΅ ΡΠΈΠΌΠ°Π½ΠΎΠ²Ρ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΡ, ΡΠ°ΠΊΠΈΠ΅ ΠΊΠ°ΠΊ ΡΡΠ΅ΡΠ° ΠΈΠ»ΠΈ ΡΠΎΡ, Π½Π΅ ΠΌΠΎΠ³ΡΡ Π±ΡΡΡ Π΄ΠΈΡΡΠ΅ΠΎΠΌΠΎΡΡΠ½Ρ Π΅Π²ΠΊΠ»ΠΈΠ΄ΠΎΠ²Ρ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Ρ ΠΈΠ·-Π·Π° ΡΠ²ΠΎΠ΅ΠΉ Π½Π΅ΡΡΠΈΠ²ΠΈΠ°Π»ΡΠ½ΠΎΠΉ ΡΠΎΠΏΠΎΠ»ΠΎΠ³ΠΈΠΈ.
every differentiable manifold can be realized as a smooth submanifold of some Cartesian space.
ΠΊΠ°ΠΆΠ΄ΠΎΠ΅ Π΄ΠΈΡΡΠ΅ΡΠ΅Π½ΡΠΈΡΡΠ΅ΠΌΠΎΠ΅ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠ΅ ΠΌΠΎΠΆΠ½ΠΎ ΡΠ΅Π°Π»ΠΈΠ·ΠΎΠ²Π°ΡΡ ΠΊΠ°ΠΊ Π³Π»Π°Π΄ΠΊΠΎΠ΅ ΠΏΠΎΠ΄ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠ΅ Π½Π΅ΠΊΠΎΡΠΎΡΠΎΠ³ΠΎ Π΄Π΅ΠΊΠ°ΡΡΠΎΠ²Π° ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π°.
A Riemannian manifold is a differentiable manifold with a Riemannian metric.
Π ΠΈΠΌΠ°Π½ΠΎΠ²ΠΎ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠ΅ β ΡΡΠΎ Π΄ΠΈΡΡΠ΅ΡΠ΅Π½ΡΠΈΡΡΠ΅ΠΌΠΎΠ΅ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠ΅ Ρ ΡΠΈΠΌΠ°Π½ΠΎΠ²ΠΎΠΉ ΠΌΠ΅ΡΡΠΈΠΊΠΎΠΉ.
One may show that every differentiable manifold can be equipped with some Riemannian metric.
ΠΠΎΠΆΠ½ΠΎ ΠΏΠΎΠΊΠ°Π·Π°ΡΡ, ΡΡΠΎ ΠΊΠ°ΠΆΠ΄ΠΎΠ΅ Π΄ΠΈΡΡΠ΅ΡΠ΅Π½ΡΠΈΡΡΠ΅ΠΌΠΎΠ΅ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±ΡΠ°Π·ΠΈΠ΅ ΠΌΠΎΠΆΠ½ΠΎ Π½Π°Π΄Π΅Π»ΠΈΡΡ Π½Π΅ΠΊΠΎΡΠΎΡΠΎΠΉ ΡΠΈΠΌΠ°Π½ΠΎΠ²ΠΎΠΉ ΠΌΠ΅ΡΡΠΈΠΊΠΎΠΉ.