Math 2.0

Real functions Functions of several real variables Theorem

Stokes' theorem

Builds on CurlLine integral of a vector fieldFlux through a surfaceOrientable surfaceParametrised surfaceGreen's theoremGeneralised Stokes theorem

Statement

Let D⊆ℝ2D \subseteq \mathbb{R}^2 be the compact region bounded by a piecewise smooth simple closed curve γ\gamma, oriented counterclockwise. Let rr be an injective regular parametrised surface of class C2C^2 on an open set that contains DD. Let S=r(D)S = r(D) have the unit normal n=(ru×rv)/∥ru×rv∥n = (r_u \times r_v) / \| r_u \times r_v \|, and let ∂S\partial S be the closed curve r∘γr \circ \gamma. If FF is a vector field of class C1C^1 on an open set that contains SS, then ∮∂SF⋅d𝐫=∬S(∇×F)⋅n dS.\oint_{\partial S} F \cdot d\mathbf{r} = \iint_S (\nabla \times F) \cdot n \, dS.

Remarks

The left side is the circulation of FF around the boundary. The right side is the flux of the curl of FF through SS. The orientations match by the right-hand rule: with the thumb along nn, the fingers curl in the direction of ∂S\partial S. Example: for the upper unit hemisphere and F=(−y,x,0)F = (-y, x, 0), ∇×F=(0,0,2)\nabla \times F = (0, 0, 2), and both sides equal 2π2\pi. For a flat surface in the xyxy-plane, the theorem reduces to Green's theorem. The proof pulls the integrals back to DD and applies Green's theorem there.

History

The theorem first appears in a letter from William Thomson to George Stokes in 1850. Stokes set it as a question on the Smith's Prize examination at Cambridge in 1854, and the result then got his name.

Reading path

To understand this page from the ground up, read these 59 pages in order. The foundations come first.

  1. Euclidean space object
  2. Function concept
  3. Function composition concept
  4. Infimum concept
  5. Supremum concept
  6. Fréchet derivative definition
  7. Total derivative concept
  8. Function of several variables concept
  9. Vector-valued function concept
  10. Jordan measure definition
  11. Limit of a function of several variables concept
  12. Differentiable function of several variables concept
  13. Parametrised curve concept
  14. Iterated integral definition
  15. Partial derivative concept
  16. Continuity in R^n definition
  17. Differentiable function of several variables definition
  18. Partial derivative definition
  19. Gradient concept
  20. Chain rule in several variables statement
  21. Differentiable on an open set definition
  22. Double integral definition
  23. Gradient definition
  24. Higher partial derivatives definition
  25. Jacobian matrix definition
  26. Chain rule for a composition with a curve statement
  27. Fubini's theorem statement
  28. Iterated derivative definition
  29. Triple integral definition
  30. C^k function characterised by continuous derivatives statement
  31. Differential form definition
  32. Parametrised curve definition
  33. Vector field definition
  34. Wedge product of forms definition
  35. Closed curve definition
  36. Parametrised surface definition
  37. Rectifiable curve definition
  38. Conservative vector field definition
  39. Curl definition
  40. Tangent vector of a curve definition
  41. Divergence definition
  42. Line integral of a scalar field definition
  43. Line integral of a vector field definition
  44. Tangent plane and normal vector of a surface definition
  45. Regular curve definition
  46. Green's theorem statement
  47. One-form definition
  48. Surface area definition
  49. Arc length parametrisation definition
  50. Surface integral definition
  51. Divergence theorem on a rectangle in the plane statement
  52. Line integral as an integral over the parameter interval statement
  53. Exterior derivative definition
  54. Orientable surface definition
  55. Gradient theorem statement
  56. Flux through a surface definition
  57. Divergence theorem statement
  58. Generalised Stokes theorem statement
  59. Stokes' theorem statement

Where this leads

2 pages build on this one.

Further reading

  1. Web https://en.wikipedia.org/wiki/Stokes%27_theorem, Theorem
  2. Web https://en.wikipedia.org/wiki/Stokes%27_theorem, History
About this page
Tag0AKRKVHW94
URIm2://0AKRKVHW94
Aliaseskelvin-stokes-theorem
Kindstatement, theorem
WritingW1 stated
MSC26B20
StatusThis copy of the site has no build data. Run m2 status 0AKRKVHW94.
UsesCurl, Line integral of a vector field, Flux through a surface, Orientable surface, Parametrised surface, Green's theorem, Generalised Stokes theorem
Same as

Markdown · JSON · Edit on GitHub

What this page needs for W2

  • edge about out: the concepts that the statement is about (0 of 1)
  • edge proves in: at least one proof node (0 of 1)
  • edge instance_of or illustrates in: one example that shows the statement at work (0 of 1)
  • explanation L2 (0 of 1)

The writing levels say how complete the text of a page is. They do not measure its truth.

What links here

Used by