HomotopyOperator

HomotopyOperator[fun][expr]
gives the result of the action of the Homotopy operator on an expression expr with respect to a set of functions, fun.
  • fun is the list of functions.
  • expr can be any expression including the functions and the derivatives of them.
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Let the expression between the two functions u, :
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When the Euler Operator is 0 a vector function can be found that its divergence gives back the expression using the Homotopy operator. For the one dimensional case this is equivalent to integrating the function:
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Indeed,
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Let the expression:
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Again, a vector function can be obtained via the Homotopy operator
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Indeed,
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