Modulus and phase of the reduced logarithmic derivative of the cylindrical Bessel function

Cruz, Andrés; Sesma, Javier

doi:10.1090/S0025-5718-1980-0583509-5

Modulus and phase of the reduced logarithmic derivative of the cylindrical Bessel function
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by Andrés Cruz and Javier Sesma PDF

Math. Comp. 35 (1980), 1317-1324 Request permission

Abstract:

The modulus and phase of the reduced logarithmic derivative of the cylindrical Bessel function \[ z{J\prime _v}(z)/{J_v}(z),\] for complex variable z and real order v, are investigated. Special attention is paid to the location of saddle points and their trajectories as v varies.

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