A Bessel function Neumann series is a series expansion of a function of a complex
variable 
in terms of Bessel
functions of the first kind, given by
 |
(1)
|
where 
is a real.
This use of the name is distinct from the Neumann series of an operator.
Special cases include
 |
(2)
|
where 
is the gamma function, and
 |
(3)
|
where
 |
(4)
|
and 
is the floor function.
