Asymptotic formulae for the Lommel and Bessel functions and their   derivatives
  We derive new approximate representations of the Lommel functions in terms of the Scorer function and approximate representations of the first derivative of the Lommel functions in terms of the derivative of the Scorer function. Using the same method we obtain previously known approximate representations of the Nicholson type for Bessel functions and their first derivatives. We study also for what values of the parameters our representations have reasonable accuracy. 
Nadezhda Aleksandrova
math.CA math-ph math.MP