The name "Sommerfeld's formula" is used for at least two equations. The first is
where
is a Bessel function of the first kind.
The second states that under appropriate restrictions,
The name "Sommerfeld's formula" is used for at least two equations. The first is
where
is a Bessel function of the first kind.
The second states that under appropriate restrictions,
Weisstein, Eric W. "Sommerfeld's Formula." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/SommerfeldsFormula.html