How Do You Solve This Complex Bessel Function Integral?

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SUMMARY

The discussion focuses on solving the complex integral of the product of two Bessel functions, specifically the integral \(\int^{2a}_{0}dp J[0,b\sqrt{p}] J[0,b\sqrt{2a-p}]\). Participants suggest expanding both Bessel functions into series and applying Cauchy's product rule for series multiplication. The change of variables \(p=2au\) is recommended to simplify the integral further. The conversation emphasizes the importance of convergence issues, although some participants choose to overlook them temporarily to achieve results.

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[tex]\int^{2a}_{0}dpJ[0,b\sqrt{p}]J[0,b\sqrt{2a-p}][/tex]

where a and b are constant, and J[0,x] is Bessel function.
 
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xylai said:
[tex]\int^{2a}_{0}dpJ[0,b\sqrt{p}]J[0,b\sqrt{2a-p}][/tex]

where a and b are constant, and J[0,x] is Bessel function.

Expand out both Bessel functions as a series and multiply them according to Cauchy's rule, namely

[tex]\left(\sum_{k=0}^{\infty}a_{k} x^{k}\right) \left(\sum_{j=0}^{\infty}b_{j} x^{j}\right) = \sum_{k=0}^{\infty}\sum_{j=0}^{k}a_{j}b_{k-j} x^k[/tex]​

and pass the integral through to the inner most sum (the second time I've blatantly ignored convergence issues, perfering to hand-wave such until I get a result) and make the change of variables [itex]p=2au[/itex], you should get it from there... post your result so I can compare/check my work.

Ben
 

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