Integral curves of vector fields on a manifold #
Let M be a manifold and v : (x : M) → TangentSpace I x be a vector field on M. An integral
curve of v is a function γ : ℝ → M such that the derivative of γ at t equals v (γ t). The
integral curve may only be defined for all t within some subset of ℝ.
This is the first of a series of files, organised as follows:
Mathlib/Geometry/Manifold/IntegralCurve/Basic.lean(this file): Basic definitions and lemmas relating them to each other and to continuity and differentiabilityMathlib/Geometry/Manifold/IntegralCurve/Transform.lean: Lemmas about translating or scaling the domain of an integral curve by a constantMathlib/Geometry/Manifold/IntegralCurve/ExistUnique.lean: Local existence and uniqueness theorems for integral curves
Main definitions #
Let v : M → TM be a vector field on M, and let γ : ℝ → M.
IsMIntegralCurve γ v:γ tis tangent tov (γ t)for allt : ℝ. That is,γis a global integral curve ofv.IsMIntegralCurveOn γ v s:γ tis tangent tov (γ t)for allt ∈ s, wheres : Set ℝ.IsMIntegralCurveAt γ v t₀:γ tis tangent tov (γ t)for alltin some open interval aroundt₀. That is,γis a local integral curve ofv.
For IsMIntegralCurveOn γ v s and IsMIntegralCurveAt γ v t₀, even though γ is defined for all
time, its value outside of the set s or a small interval around t₀ is irrelevant and considered
junk.
TODO #
- Implement
IsMIntegralCurveWithinAt.
Reference #
- [Lee, J. M. (2012). Introduction to Smooth Manifolds. Springer New York.][lee2012]
Tags #
integral curve, vector field
If γ : ℝ → M is $C^1$ on s : Set ℝ and v is a vector field on M,
IsMIntegralCurveOn γ v s means γ t is tangent to v (γ t) for all t ∈ s. The value of γ
outside of s is irrelevant and considered junk.
Equations
- IsMIntegralCurveOn γ v s = ∀ t ∈ s, HasMFDerivWithinAt (modelWithCornersSelf ℝ ℝ) I γ s t (ContinuousLinearMap.smulRight 1 (v (γ t)))
Instances For
Alias of IsMIntegralCurveOn.
If γ : ℝ → M is $C^1$ on s : Set ℝ and v is a vector field on M,
IsMIntegralCurveOn γ v s means γ t is tangent to v (γ t) for all t ∈ s. The value of γ
outside of s is irrelevant and considered junk.
Equations
Instances For
If v is a vector field on M and t₀ : ℝ, IsMIntegralCurveAt γ v t₀ means γ : ℝ → M is a
local integral curve of v in a neighbourhood containing t₀. The value of γ outside of this
interval is irrelevant and considered junk.
Equations
- IsMIntegralCurveAt γ v t₀ = ∀ᶠ (t : ℝ) in nhds t₀, HasMFDerivAt (modelWithCornersSelf ℝ ℝ) I γ t (ContinuousLinearMap.smulRight 1 (v (γ t)))
Instances For
Alias of IsMIntegralCurveAt.
If v is a vector field on M and t₀ : ℝ, IsMIntegralCurveAt γ v t₀ means γ : ℝ → M is a
local integral curve of v in a neighbourhood containing t₀. The value of γ outside of this
interval is irrelevant and considered junk.
Equations
Instances For
If v : M → TM is a vector field on M, IsMIntegralCurve γ v means γ : ℝ → M is a global
integral curve of v. That is, γ t is tangent to v (γ t) for all t : ℝ.
Equations
- IsMIntegralCurve γ v = ∀ (t : ℝ), HasMFDerivAt (modelWithCornersSelf ℝ ℝ) I γ t (ContinuousLinearMap.smulRight 1 (v (γ t)))
Instances For
Alias of IsMIntegralCurve.
If v : M → TM is a vector field on M, IsMIntegralCurve γ v means γ : ℝ → M is a global
integral curve of v. That is, γ t is tangent to v (γ t) for all t : ℝ.
Equations
Instances For
Alias of IsMIntegralCurve.isMIntegralCurveOn.
Alias of isMIntegralCurve_iff_isMIntegralCurveOn.
Alias of isMIntegralCurveAt_iff.
γ is an integral curve for v at t₀ iff γ is an integral curve on some interval
containing t₀.
Alias of isMIntegralCurveAt_iff'.
γ is an integral curve for v at t₀ iff γ is an integral curve on some interval
containing t₀.
Alias of IsMIntegralCurve.isMIntegralCurveAt.
Alias of isMIntegralCurve_iff_isMIntegralCurveAt.
Alias of IsMIntegralCurveOn.mono.
Alias of IsMIntegralCurveAt.hasMFDerivAt.
Alias of IsMIntegralCurveOn.isMIntegralCurveAt.
If γ is an integral curve at each t ∈ s, it is an integral curve on s.
Alias of IsMIntegralCurveAt.isMIntegralCurveOn.
If γ is an integral curve at each t ∈ s, it is an integral curve on s.
Alias of IsMIntegralCurveOn.continuousWithinAt.
Alias of IsMIntegralCurveOn.continuousWithinAt.
Alias of IsMIntegralCurveOn.continuousOn.
Alias of IsMIntegralCurveAt.continuousAt.
Alias of IsMIntegralCurve.continuous.
If γ is an integral curve of a vector field v, then γ t is tangent to v (γ t) when
expressed in the local chart around the initial point γ t₀.
Alias of IsMIntegralCurveOn.hasDerivWithinAt.
If γ is an integral curve of a vector field v, then γ t is tangent to v (γ t) when
expressed in the local chart around the initial point γ t₀.
Alias of IsMIntegralCurveAt.eventually_hasDerivAt.