Is there any hope with this integral?












0












$begingroup$


I can't figure out how to take this integral. Looks pretty standard to me, but somehow can't find anything helpful in the literature:



$int_0^{2pi} dphi; (1-2 a cos phi + a^2)^{k+ (kappa/2)} e^{-i( ell - kappa) phi} $



MMA is stuck with it as well, which makes me suspicious if the closed form exists...



Any help with this is highly appreciated!










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  • $begingroup$
    One can write $1-2a cosphi+a^2=(a-e^{i phi})(a-e^{-i phi})=|a-e^{i phi}|^2$ ; I would then try integration by residues.
    $endgroup$
    – Jean Marie
    Dec 13 '18 at 18:08












  • $begingroup$
    @Jean Marie Thank you for the idea! I'll try it out.
    $endgroup$
    – MsTais
    Dec 13 '18 at 18:36
















0












$begingroup$


I can't figure out how to take this integral. Looks pretty standard to me, but somehow can't find anything helpful in the literature:



$int_0^{2pi} dphi; (1-2 a cos phi + a^2)^{k+ (kappa/2)} e^{-i( ell - kappa) phi} $



MMA is stuck with it as well, which makes me suspicious if the closed form exists...



Any help with this is highly appreciated!










share|cite|improve this question









$endgroup$












  • $begingroup$
    One can write $1-2a cosphi+a^2=(a-e^{i phi})(a-e^{-i phi})=|a-e^{i phi}|^2$ ; I would then try integration by residues.
    $endgroup$
    – Jean Marie
    Dec 13 '18 at 18:08












  • $begingroup$
    @Jean Marie Thank you for the idea! I'll try it out.
    $endgroup$
    – MsTais
    Dec 13 '18 at 18:36














0












0








0





$begingroup$


I can't figure out how to take this integral. Looks pretty standard to me, but somehow can't find anything helpful in the literature:



$int_0^{2pi} dphi; (1-2 a cos phi + a^2)^{k+ (kappa/2)} e^{-i( ell - kappa) phi} $



MMA is stuck with it as well, which makes me suspicious if the closed form exists...



Any help with this is highly appreciated!










share|cite|improve this question









$endgroup$




I can't figure out how to take this integral. Looks pretty standard to me, but somehow can't find anything helpful in the literature:



$int_0^{2pi} dphi; (1-2 a cos phi + a^2)^{k+ (kappa/2)} e^{-i( ell - kappa) phi} $



MMA is stuck with it as well, which makes me suspicious if the closed form exists...



Any help with this is highly appreciated!







integration definite-integrals exponential-function






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 13 '18 at 17:57









MsTaisMsTais

1808




1808












  • $begingroup$
    One can write $1-2a cosphi+a^2=(a-e^{i phi})(a-e^{-i phi})=|a-e^{i phi}|^2$ ; I would then try integration by residues.
    $endgroup$
    – Jean Marie
    Dec 13 '18 at 18:08












  • $begingroup$
    @Jean Marie Thank you for the idea! I'll try it out.
    $endgroup$
    – MsTais
    Dec 13 '18 at 18:36


















  • $begingroup$
    One can write $1-2a cosphi+a^2=(a-e^{i phi})(a-e^{-i phi})=|a-e^{i phi}|^2$ ; I would then try integration by residues.
    $endgroup$
    – Jean Marie
    Dec 13 '18 at 18:08












  • $begingroup$
    @Jean Marie Thank you for the idea! I'll try it out.
    $endgroup$
    – MsTais
    Dec 13 '18 at 18:36
















$begingroup$
One can write $1-2a cosphi+a^2=(a-e^{i phi})(a-e^{-i phi})=|a-e^{i phi}|^2$ ; I would then try integration by residues.
$endgroup$
– Jean Marie
Dec 13 '18 at 18:08






$begingroup$
One can write $1-2a cosphi+a^2=(a-e^{i phi})(a-e^{-i phi})=|a-e^{i phi}|^2$ ; I would then try integration by residues.
$endgroup$
– Jean Marie
Dec 13 '18 at 18:08














$begingroup$
@Jean Marie Thank you for the idea! I'll try it out.
$endgroup$
– MsTais
Dec 13 '18 at 18:36




$begingroup$
@Jean Marie Thank you for the idea! I'll try it out.
$endgroup$
– MsTais
Dec 13 '18 at 18:36










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