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advanced_tools:exterior_derivative [2023/03/12 17:37]
edi [Intuitive]
advanced_tools:exterior_derivative [2023/03/19 21:27]
edi [Intuitive]
Line 4: Line 4:
 The exterior derivative generalizes the curl operator from 3-dimensional space to any number of dimensions. The exterior derivative generalizes the curl operator from 3-dimensional space to any number of dimensions.
  
-The exterior derivative of a vector field $v$ can be written as $\nabla \wedge v$, where the $\wedge$ indicates the exterior product. This is analogous to how we can write the curl as $\nabla \times v$, where $\times$ is the cross product, and the divergence as $\nabla \cdot v$, where $\cdot$ is the dot product.+The exterior derivative of a vector field $v$ can be written as $\nabla \wedge v$, where the $\wedge$ indicates the [[advanced_tools:​exterior_product|exterior product]]. This is analogous to how we can write the curl as $\nabla \times v$, where $\times$ is the cross product, and the divergence as $\nabla \cdot v$, where $\cdot$ is the dot product. The result of $\nabla \wedge v$ is an anti-symmetric tensor field
  
-The curl operator ​in 3D is the Hodge dual of the exterior derivative: ${\rm curl}(v) = \star(\nabla \wedge v)$.+In 3-dimensional space, the curl operator is equal to the [[advanced_tools:​hodge_dual|Hodge dual]] of the exterior derivative: ${\rm curl}(v) = \star(\nabla \wedge v)$.
  
-The exterior derivative of a $p$-form $\omega$ is usually ​written as $d\omega$.+The exterior derivative of a $p$-form $\omega$ is commonly ​written as $d\omega$. The result of $d\omega$ is a ($p+1$)-form.
  
-Taking the exterior derivative of any object ​twice results in zero: $d^2\omega=0$. This is an important result with many implications ​including ​for the electrodynamics ​and topology.+Taking the exterior derivative ​twice (of any objectresults in zero: $d^2\omega=0$. This is an important result with many implications for electrodynamicstopology, etc.
  
        
 <tabbox Concrete> ​ <tabbox Concrete> ​
 +The diagram shows on the left-hand side how the gradient, curl, and divergence operators know from 3D can be constructed from the exterior derivative and the Hodge dual. The right-hand side illustrates the fact that taking the exterior derivative twice results in zero. 
 +
 +For a more detailed explanation of this picture see [[https://​esackinger.wordpress.com/​|Fun with Symmetry]].
 +
 +[{{ :​advanced_tools:​exterior_deriv.jpg?​nolink }}]
  
-<note tip> 
-In this section things should be explained by analogy and with pictures and, if necessary, some formulas. 
-</​note>​ 
-  
 <tabbox Abstract> ​ <tabbox Abstract> ​
  
advanced_tools/exterior_derivative.txt ยท Last modified: 2023/03/19 21:28 by edi