|  Bessel Functions | 
In General > s.a. integration [Poisson integral].
  $ Def: Solutions of the ordinary
    differential equation (Bessel's equation) x2
    F''(x) + x F'(x) + (x2
    − n2) F(x) = 0.
  * Types: First kind,
    Jn
    and J−n;
    Second kind, Yn
    and Y−n,
    or Nn
    and N−n,
    a.k.a. Neumann or Weber functions; Third kind,
    H 1,2n,
    a.k.a. Hankel functions.
  * Asymptotic behavior:
    Near x = 0, Jn
    ∝ xn is regular,
    Nn
    ∝ x−n,
    or ln x if n = 0, blows up; For x →
    ∞, Jn and
    Nn are oscillatory and go to 0.
  * Zeroes: They all have an infinite
    number; For Jn(x),
    the higher roots are given by xn,k
    ≈ kπ + (n−\(1\over2\)) π/2.
  * Power series expansion:
Jn(x) = (2n n!)−1 xn {1 − [22 1! (n+1)]−1 x2 + [24 2! (n+1) (n+2)]−1 x4 − ...} .
* Recursion relations: They all satisfy
Fn−1(x) + Fn+1(x) = (2n/x) Fn(x) ; dFn(x)/dx = −Fn+1 + (n/x) Fn = \(1\over2\)[Fn−1(x) − Fn+1(x)] .
  $ Parseval's integral:
    \(J_0(z) = (1/\pi) \int_0^\infty{\rm d}\theta\,\cos(z\cos\theta)\).
  @ General references: Watson 44;
    in Abramowitz & Stegun 65;
    in Arfken 85;
    Howls & Daalhuis PRS(99) [asymptotics];
    Bailey et al JPA(08)-a0801 [results on moments, and mathematical physics];
    Yuste & Abad JPA(11)-a1101 [polynomial approximations].
  @ Relationships and related topics:
    Mekhfi IJTP(00);
    Mekhfi  mp/00 [deformed derivatives];
    Durand JMP(03)mp/02 [fractional operators];
    Cosmin a0912
      [integral involving the product of four Bessel functions];
    Babusci a1110 [integrals];
    Dominici et al PRS(12) [identity involving integrals and sums];
    Babusci et al JMP(13)-a1209 [evaluation of sum rules];
    Dattoli et al a1311
      [products of Bessel functions and their integrals];
    > s.a. Whittaker Functions.
Other Related Bessel Functions > s.a. Struve Functions.
  * Spherical:
j0(x) = (sin x)/x , j1(x) = (sin x)/x2 − (cos x)/x , j2(x) = 3 (sin x)/x3 − 3 (cos x)/x2 − (sin x)/x .
  @ Spherical: Ludu & O'Connell PS(02)mp/01 [Laplace transform];
    Boersma & Glasser JPA(05) [differentiation formula];
    Mehrem & Hohenegger JPA(10)-a1006 [infinite integral over three spherical Bessel functions];
    Mehrem a1110
      [integral involving two spherical Bessel functions].
  @ Modified: Bender et al JMP(03) [Taylor expansions of powers].
  @ Modified, McDonald functions Ka:
    Maslanka mp/01 [series representations and fractional derivatives].
  @ In Minkowski space: Gerlach PRD(88)gq/99.
  @ Other generalizations:
    Boyer JMP(69) [Riccati-Bessel functions, zeros];
    Lizzi et al JHEP(05)ht [on the fuzzy disk];
    Korsch et al JPA(06)qp [2D].
 main page
  – abbreviations
  – journals – comments
  – other sites – acknowledgements
  send feedback and suggestions to bombelli at olemiss.edu – modified 14 jan 2016