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10 Bessel FunctionsBessel and Hankel Functions

§10.22 Integrals

Contents
  1. §10.22(i) Indefinite Integrals
  2. §10.22(ii) Integrals over Finite Intervals
  3. §10.22(iii) Integrals over the Interval (x,∞)
  4. §10.22(iv) Integrals over the Interval (0,∞)
  5. §10.22(v) Hankel Transform
  6. §10.22(vi) Compendia

§10.22(i) Indefinite Integrals

In this subsection 𝒞ν⁡(z) and 𝒟μ⁡(z) denote cylinder functions(§10.2(ii)) of orders ν and μ, respectively, not necessarily distinct.

10.22.1 ∫zν+1⁢𝒞ν⁡(z)⁢dz =zν+1⁢𝒞ν+1⁡(z),
∫z−ν+1⁢𝒞ν⁡(z)⁢dz =−z−ν+1⁢𝒞ν−1⁡(z).
10.22.2 ∫zν⁢𝒞ν⁡(z)⁢dz=π12⁢2ν−1⁢Γ⁡(ν+12)⁢z⁢(𝒞ν⁡(z)⁢𝐇ν−1⁡(z)−𝒞ν−1⁡(z)⁢𝐇ν⁡(z)),
ν≠−12.

For the Struve function 𝐇ν⁡(z) see §11.2(i).

10.22.3 ∫ei⁢z⁢zν⁢𝒞ν⁡(z)⁢dz =ei⁢z⁢zν+12⁢ν+1⁢(𝒞ν⁡(z)−i⁢𝒞ν+1⁡(z)),
ν≠−12,
∫ei⁢z⁢z−ν⁢𝒞ν⁡(z)⁢dz =ei⁢z⁢z−ν+11−2⁢ν⁢(𝒞ν⁡(z)+i⁢𝒞ν−1⁡(z)),
ν≠12.

Products

10.22.4 ∫z⁢𝒞μ⁡(a⁢z)⁢𝒟μ⁡(b⁢z)⁢dz=z⁢(a⁢𝒞μ+1⁡(a⁢z)⁢𝒟μ⁡(b⁢z)−b⁢𝒞μ⁡(a⁢z)⁢𝒟μ+1⁡(b⁢z))a2−b2,
a2≠b2,
10.22.5 ∫z⁢𝒞μ⁡(a⁢z)⁢𝒟μ⁡(a⁢z)⁢dz =14⁢z2⁢(2⁢𝒞μ⁡(a⁢z)⁢𝒟μ⁡(a⁢z)−𝒞μ−1⁡(a⁢z)⁢𝒟μ+1⁡(a⁢z)−𝒞μ+1⁡(a⁢z)⁢𝒟μ−1⁡(a⁢z)),
10.22.6 ∫𝒞μ⁡(a⁢z)⁢𝒟ν⁡(a⁢z)⁢dzz =−a⁢z⁢(𝒞μ+1⁡(a⁢z)⁢𝒟ν⁡(a⁢z)−𝒞μ⁡(a⁢z)⁢𝒟ν+1⁡(a⁢z))μ2−ν2+𝒞μ⁡(a⁢z)⁢𝒟ν⁡(a⁢z)μ+ν,
μ2≠ν2,
10.22.7 ∫zμ+ν+1⁢𝒞μ⁡(a⁢z)⁢𝒟ν⁡(a⁢z)⁢dz =zμ+ν+22⁢(μ+ν+1)⁢(𝒞μ⁡(a⁢z)⁢𝒟ν⁡(a⁢z)+𝒞μ+1⁡(a⁢z)⁢𝒟ν+1⁡(a⁢z)),
μ+ν≠−1,
∫z−μ−ν+1⁢𝒞μ⁡(a⁢z)⁢𝒟ν⁡(a⁢z)⁢dz =z−μ−ν+22⁢(1−μ−ν)⁢(𝒞μ⁡(a⁢z)⁢𝒟ν⁡(a⁢z)+𝒞μ−1⁡(a⁢z)⁢𝒟ν−1⁡(a⁢z)),
μ+ν≠1.

§10.22(ii) Integrals over Finite Intervals

Throughout this subsection x>0.

10.22.8 ∫0xJν⁡(t)⁢dt=2⁢∑k=0∞Jν+2⁢k+1⁡(x),
ℜ⁡ν>−1.
10.22.9 ∫0xJ2⁢n⁡(t)⁢dt=∫0xJ0⁡(t)⁢dt−2⁢∑k=0n−1J2⁢k+1⁡(x),∫0xJ2⁢n+1⁡(t)⁢dt=1−J0⁡(x)−2⁢∑k=1nJ2⁢k⁡(x),
n=0,1,….
10.22.10 ∫0xtμ⁢Jν⁡(t)⁢dt=xμ⁢Γ⁡(12⁢ν+12⁢μ+12)Γ⁡(12⁢ν−12⁢μ+12)⁢∑k=0∞(ν+2⁢k+1)⁢Γ⁡(12⁢ν−12⁢μ+12+k)Γ⁡(12⁢ν+12⁢μ+32+k)⁢Jν+2⁢k+1⁡(x),
ℜ⁡(μ+ν+1)>0.
10.22.11 ∫0x1−J0⁡(t)t⁢dt =12⁢∑k=1∞ψ⁡(k+1)−ψ⁡(1)k!⁢(12⁢x)k⁢Jk⁡(x),
10.22.12 x⁢∫0x1−J0⁡(t)t⁢dt =2⁢∑k=0∞(2⁢k+3)⁢(ψ⁡(k+2)−ψ⁡(1))⁢J2⁢k+3⁡(x)=x−2⁢J1⁡(x)+2⁢∑k=0∞(2⁢k+5)⁢(ψ⁡(k+3)−ψ⁡(1)−1)⁢J2⁢k+5⁡(x),

where ψ⁡(x)=Γ′⁡(x)/Γ⁡(x) (§5.2(i)). See also (10.22.39).

Trigonometric Arguments

10.22.13 ∫012⁢πJ2⁢ν⁡(2⁢z⁢cos⁡θ)⁢cos⁡(2⁢μ⁢θ)⁢dθ =12⁢π⁢Jν+μ⁡(z)⁢Jν−μ⁡(z),
ℜ⁡ν>−12,
10.22.14 ∫0πJ2⁢ν⁡(2⁢z⁢sin⁡θ)⁢cos⁡(2⁢μ⁢θ)⁢dθ =π⁢cos⁡(μ⁢π)⁢Jν+μ⁡(z)⁢Jν−μ⁡(z),
ℜ⁡ν>−12,
10.22.15 ∫0πJ2⁢ν⁡(2⁢z⁢sin⁡θ)⁢sin⁡(2⁢μ⁢θ)⁢dθ =π⁢sin⁡(μ⁢π)⁢Jν+μ⁡(z)⁢Jν−μ⁡(z),
ℜ⁡ν>−1.
10.22.16 ∫012⁢πJ0⁡(2⁢z⁢sin⁡θ)⁢cos⁡(2⁢n⁢θ)⁢dθ =12⁢π⁢Jn2⁡(z),
n=0,1,2,….
10.22.17 ∫012⁢πY2⁢ν⁡(2⁢z⁢cos⁡θ)⁢cos⁡(2⁢μ⁢θ)⁢dθ=12⁢π⁢cot⁡(2⁢ν⁢π)⁢Jν+μ⁡(z)⁢Jν−μ⁡(z)−12⁢π⁢csc⁡(2⁢ν⁢π)⁢Jμ−ν⁡(z)⁢J−μ−ν⁡(z),
−12<ℜ⁡ν<12,
10.22.18 ∫012⁢πY0⁡(2⁢z⁢sin⁡θ)⁢cos⁡(2⁢n⁢θ)⁢dθ=12⁢π⁢Jn⁡(z)⁢Yn⁡(z),
n=0,1,2,….
10.22.19 ∫012⁢πJμ⁡(z⁢sin⁡θ)⁢(sin⁡θ)μ+1⁢(cos⁡θ)2⁢ν+1⁢dθ=2ν⁢Γ⁡(ν+1)⁢z−ν−1⁢Jμ+ν+1⁡(z),
ℜ⁡μ>−1, ℜ⁡ν>−1,
10.22.20 ∫012⁢πJμ⁡(z⁢sin⁡θ)⁢(sin⁡θ)μ⁢(cos⁡θ)2⁢μ⁢dθ =π12⁢2μ−1⁢z−μ⁢Γ⁡(μ+12)⁢Jμ2⁡(12⁢z),
ℜ⁡μ>−12,
10.22.21 ∫012⁢πYμ⁡(z⁢sin⁡θ)⁢(sin⁡θ)μ⁢(cos⁡θ)2⁢μ⁢dθ =π12⁢2μ−1⁢z−μ⁢Γ⁡(μ+12)⁢Jμ⁡(12⁢z)⁢Yμ⁡(12⁢z),
ℜ⁡μ>−12.
10.22.22 ∫012⁢πJμ⁡(z⁢sin2⁡θ)⁢Jν⁡(z⁢cos2⁡θ)⁢(sin⁡θ)2⁢μ+1⁢(cos⁡θ)2⁢ν+1⁢dθ=Γ⁡(μ+12)⁢Γ⁡(ν+12)⁢Jμ+ν+12⁡(z)(8⁢π⁢z)12⁢Γ⁡(μ+ν+1),
ℜ⁡μ>−12,ℜ⁡ν>−12.
10.22.23 ∫012⁢πJμ⁡(z⁢sin2⁡θ)⁢Jν⁡(z⁢cos2⁡θ)⁢(sin⁡θ)2⁢α−1⁢sec⁡θ⁢dθ =(μ+ν+α)⁢Γ⁡(μ+α)⁢2α−1ν⁢Γ⁡(μ+1)⁢zα⁢Jμ+ν+α⁡(z),
ℜ⁡(μ+α)>0, ℜ⁡ν>0.
10.22.24 ∫012⁢πJμ⁡(z⁢sin2⁡θ)⁢Jν⁡(z⁢cos2⁡θ)⁢cot⁡θ⁢dθ =12⁢μ−1⁢Jμ+ν⁡(z),
ℜ⁡μ>0,ℜ⁡ν>−1.
10.22.25 ∫012⁢πJμ⁡(z⁢sin⁡θ)⁢Iν⁡(z⁢cos⁡θ)⁢(tan⁡θ)μ+1⁢dθ =Γ⁡(12⁢ν−12⁢μ)⁢(12⁢z)μ2⁢Γ⁡(12⁢ν+12⁢μ+1)⁢Jν⁡(z),
ℜ⁡ν>ℜ⁡μ>−1.

For Iν see §10.25(ii).

10.22.26 ∫012⁢πJμ⁡(z⁢sin⁡θ)⁢Jν⁡(ζ⁢cos⁡θ)⁢(sin⁡θ)μ+1⁢(cos⁡θ)ν+1⁢dθ=zμ⁢ζν⁢Jμ+ν+1⁡(ζ2+z2)(ζ2+z2)12⁢(μ+ν+1),
ℜ⁡μ>−1,ℜ⁡ν>−1.

Products

10.22.27 ∫0xt⁢Jν−12⁡(t)⁢dt =2⁢∑k=0∞(ν+2⁢k)⁢Jν+2⁢k2⁡(x),
ℜ⁡ν>0,
10.22.28 ∫0xt⁢(Jν−12⁡(t)−Jν+12⁡(t))⁢dt =2⁢ν⁢Jν2⁡(x),
ℜ⁡ν>0,
10.22.29 ∫0xt⁢J02⁡(t)⁢dt =12⁢x2⁢(J02⁡(x)+J12⁡(x)).
10.22.30 ∫0xJn⁡(t)⁢Jn+1⁡(t)⁢dt=12⁢(1−J02⁡(x))−∑k=1nJk2⁡(x)=∑k=n+1∞Jk2⁡(x),
n=0,1,2,….

Convolutions

10.22.31 ∫0xJμ⁡(t)⁢Jν⁡(x−t)⁢dt=2⁢∑k=0∞(−1)k⁢Jμ+ν+2⁢k+1⁡(x),
ℜ⁡μ>−1,ℜ⁡ν>−1.
10.22.32 ∫0xJν⁡(t)⁢J1−ν⁡(x−t)⁢dt =J0⁡(x)−cos⁡x,
−1<ℜ⁡ν<2.
10.22.33 ∫0xJν⁡(t)⁢J−ν⁡(x−t)⁢dt =sin⁡x,
|ℜ⁡ν|<1.
10.22.34 ∫0xt−1⁢Jμ⁡(t)⁢Jν⁡(x−t)⁢dt=Jμ+ν⁡(x)μ,
ℜ⁡μ>0,ℜ⁡ν>−1.
10.22.35 ∫0xJμ⁡(t)⁢Jν⁡(x−t)⁢dtt⁢(x−t)=(μ+ν)⁢Jμ+ν⁡(x)μ⁢ν⁢x,
ℜ⁡μ>0,ℜ⁡ν>0.

Fractional Integral

10.22.36 1Γ⁡(α)⁢∫0x(x−t)α−1⁢Jν⁡(t)⁢dt=2α⁢∑k=0∞(α)kk!⁢Jν+α+2⁢k⁡(x),
ℜ⁡α>0,ℜ⁡ν≥0.

When α=m=1,2,3,… the left-hand side of (10.22.36) is the mth repeated integral of Jν⁡(x) (§§1.4(v) and 1.15(vi)).

Orthogonality

If ν>−1, then

10.22.37 ∫01t⁢Jν⁡(jν,ℓ⁢t)⁢Jν⁡(jν,m⁢t)⁢dt=12⁢(Jν′⁡(jν,ℓ))2⁢δℓ,m,

where jν,ℓ and jν,m are zeros of Jν⁡(x) (§10.21(i)), and δℓ,m is Kronecker’s symbol.

Also, if a,b,ν are real constants with b≠0 and ν>−1, then

10.22.38 ∫01t⁢Jν⁡(αℓ⁢t)⁢Jν⁡(αm⁢t)⁢dt=(a2b2+αℓ2−ν2)⁢(Jν⁡(αℓ))22⁢αℓ2⁢δℓ,m,

where αℓ and αm are positive zeros of a⁢Jν⁡(x)+b⁢x⁢Jν′⁡(x). (Compare (10.22.55)).

§10.22(iii) Integrals over the Interval (x,∞)

When x>0

10.22.39 ∫x∞J0⁡(t)t⁢dt+γ+ln⁡(12⁢x)=∫0x1−J0⁡(t)t⁢dt=∑k=1∞(−1)k−1⁢(12⁢x)2⁢k2⁢k⁢(k!)2,
10.22.40 ∫x∞Y0⁡(t)t⁢dt=−1π⁢(ln⁡(12⁢x)+γ)2+π6+2π⁢∑k=1∞(−1)k⁢(ψ⁡(k+1)+12⁢k−ln⁡(12⁢x))⁢(12⁢x)2⁢k2⁢k⁢(k!)2,

where γ is Euler’s constant (§5.2(ii)). Compare (10.22.11) and (10.22.12).

§10.22(iv) Integrals over the Interval (0,∞)

10.22.41 ∫0∞Jν⁡(t)⁢dt =1,
ℜ⁡ν>−1,
10.22.42 ∫0∞Yν⁡(t)⁢dt =−tan⁡(12⁢ν⁢π),
|ℜ⁡ν|<1.
10.22.43 ∫0∞tμ⁢Jν⁡(t)⁢dt =2μ⁢Γ⁡(12⁢ν+12⁢μ+12)Γ⁡(12⁢ν−12⁢μ+12),
ℜ⁡(μ+ν)>−1, ℜ⁡μ<12,
10.22.44 ∫0∞tμ⁢Yν⁡(t)⁢dt =2μπ⁢Γ⁡(12⁢μ+12⁢ν+12)⁢Γ⁡(12⁢μ−12⁢ν+12)⁢sin⁡(12⁢μ−12⁢ν)⁢π,
ℜ⁡(μ±ν)>−1, ℜ⁡μ<12.
10.22.45 ∫0∞1−J0⁡(t)tμ⁢dt=−π⁢sec⁡(12⁢μ⁢π)2μ⁢Γ2⁡(12⁢μ+12),
1<ℜ⁡μ<3.
10.22.46 ∫0∞tν+1⁢Jν⁡(a⁢t)(t2+b2)μ+1⁢dt=aμ⁢bν−μ2μ⁢Γ⁡(μ+1)⁢Kν−μ⁡(a⁢b),
a>0, ℜ⁡b>0, −1<ℜ⁡ν<2⁢ℜ⁡μ+32.
10.22.47 ∫0∞tν⁢Yν⁡(a⁢t)t2+b2⁢dt=−bν−1⁢Kν⁡(a⁢b),
a>0,ℜ⁡b>0,−12<ℜ⁡ν<52.

For Kν see §10.25(ii).

10.22.48 ∫0∞Jμ⁡(x⁢cosh⁡ϕ)⁢(cosh⁡ϕ)1−μ⁢(sinh⁡ϕ)2⁢ν+1⁢dϕ=2ν⁢Γ⁡(ν+1)⁢x−ν−1⁢Jμ−ν−1⁡(x),
x>0,ℜ⁡ν>−1,ℜ⁡μ>2⁢ℜ⁡ν+12.
10.22.49 ∫0∞tμ−1⁢e−a⁢t⁢Jν⁡(b⁢t)⁢dt=(12⁢b)νaμ+ν⁢Γ⁡(μ+ν)⁢𝐅⁡(μ+ν2,μ+ν+12;ν+1;−b2a2),
ℜ⁡(μ+ν)>0,ℜ⁡(a±i⁢b)>0,
10.22.50 ∫0∞tμ−1⁢e−a⁢t⁢Yν⁡(b⁢t)⁢dt=cot⁡(ν⁢π)⁢(12⁢b)ν⁢Γ⁡(μ+ν)(a2+b2)12⁢(μ+ν)⁢𝐅⁡(μ+ν2,1−μ+ν2;ν+1;b2a2+b2)−csc⁡(ν⁢π)⁢(12⁢b)−ν⁢Γ⁡(μ−ν)(a2+b2)12⁢(μ−ν)⁢𝐅⁡(μ−ν2,1−μ−ν2;1−ν;b2a2+b2),
ℜ⁡μ>|ℜ⁡ν|,ℜ⁡(a±i⁢b)>0.

For the hypergeometric function 𝐅 see §15.2(i).

10.22.51 ∫0∞Jν⁡(b⁢t)⁢exp⁡(−p2⁢t2)⁢tν+1⁢dt =bν(2⁢p2)ν+1⁢exp⁡(−b24⁢p2),
ℜ⁡ν>−1, ℜ⁡(p2)>0,
10.22.52 ∫0∞Jν⁡(b⁢t)⁢exp⁡(−p2⁢t2)⁢dt =π2⁢p⁢exp⁡(−b28⁢p2)⁢Iν/2⁡(b28⁢p2),
ℜ⁡ν>−1,ℜ⁡(p2)>0,
10.22.53 ∫0∞Y2⁢ν⁡(b⁢t)⁢exp⁡(−p2⁢t2)⁢dt=−π2⁢p⁢exp⁡(−b28⁢p2)⁢(Iν⁡(b28⁢p2)⁢tan⁡(ν⁢π)+1π⁢Kν⁡(b28⁢p2)⁢sec⁡(ν⁢π)),
|ℜ⁡ν|<12, ℜ⁡(p2)>0.

For I and K see §10.25(ii).

10.22.54 ∫0∞Jν⁡(b⁢t)⁢exp⁡(−p2⁢t2)⁢tμ−1⁢dt=(12⁢b/p)ν⁢Γ⁡(12⁢ν+12⁢μ)2⁢pμ⁢exp⁡(−b24⁢p2)⁢𝐌⁡(12⁢ν−12⁢μ+1,ν+1,b24⁢p2),
ℜ⁡(μ+ν)>0, ℜ⁡(p2)>0.

For the confluent hypergeometric function 𝐌 see §13.2(i).

Orthogonality

10.22.55 ∫0∞t−1⁢Jν+2⁢ℓ+1⁡(t)⁢Jν+2⁢m+1⁡(t)⁢dt=δℓ,m2⁢(2⁢ℓ+ν+1),
ν+ℓ+m>−1.

Weber–Schafheitlin Discontinuous Integrals, including Special Cases

10.22.56 ∫0∞Jμ⁡(a⁢t)⁢Jν⁡(b⁢t)tλ⁢dt=aμ⁢Γ⁡(12⁢ν+12⁢μ−12⁢λ+12)2λ⁢bμ−λ+1⁢Γ⁡(12⁢ν−12⁢μ+12⁢λ+12)⁢𝐅⁡(12⁢(μ+ν−λ+1),12⁢(μ−ν−λ+1);μ+1;a2b2),
0<a<b, ℜ⁡(μ+ν+1)>ℜ⁡λ>−1.

If 0<b<a, then interchange a and b, and also μ and ν. If b=a, then

10.22.57 ∫0∞Jμ⁡(a⁢t)⁢Jν⁡(a⁢t)tλ⁢dt =(12⁢a)λ−1⁢Γ⁡(12⁢μ+12⁢ν−12⁢λ+12)⁢Γ⁡(λ)2⁢Γ⁡(12⁢λ+12⁢ν−12⁢μ+12)⁢Γ⁡(12⁢λ+12⁢μ−12⁢ν+12)⁢Γ⁡(12⁢λ+12⁢μ+12⁢ν+12),
ℜ⁡(μ+ν+1)>ℜ⁡λ>0.
10.22.58 ∫0∞Jν⁡(a⁢t)⁢Jν⁡(b⁢t)tλ⁢dt =(a⁢b)ν⁢Γ⁡(ν−12⁢λ+12)2λ⁢(a2+b2)ν−12⁢λ+12⁢Γ⁡(12⁢λ+12)⁢𝐅⁡(2⁢ν+1−λ4,2⁢ν+3−λ4;ν+1;4⁢a2⁢b2(a2+b2)2),
a≠b, ℜ⁡(2⁢ν+1)>ℜ⁡λ>−1.

When ℜ⁡μ>−1

10.22.59 ∫0∞ei⁢b⁢t⁢Jμ⁡(a⁢t)⁢dt={exp⁡(i⁢μ⁢arcsin⁡(b/a))(a2−b2)12,0≤b<a,i⁢aμ⁢exp⁡(12⁢μ⁢π⁢i)(b2−a2)12⁢(b+(b2−a2)12)μ,0<a<b.
10.22.60 ∫0∞ei⁢b⁢t⁢Y0⁡(a⁢t)⁢dt={(2⁢i/π)⁢(a2−b2)−12⁢arcsin⁡(b/a),0≤b<a,(b2−a2)−12⁢(−1+2⁢iπ⁢ln⁡(ab+(b2−a2)12)),0<a<b.

When ℜ⁡μ>0,

10.22.61 ∫0∞t−1⁢ei⁢b⁢t⁢Jμ⁡(a⁢t)⁢dt={(1/μ)⁢exp⁡(i⁢μ⁢arcsin⁡(b/a)),0≤b≤a,aμ⁢exp⁡(12⁢μ⁢π⁢i)μ⁢(b+(b2−a2)12)μ,0<a≤b.

When ℜ⁡ν>ℜ⁡μ>−1,

10.22.62 ∫0∞tμ−ν+1⁢Jμ⁡(a⁢t)⁢Jν⁡(b⁢t)⁢dt={0,0<b<a,2μ−ν+1⁢aμ⁢(b2−a2)ν−μ−1bν⁢Γ⁡(ν−μ),0<a≤b.

When ℜ⁡μ>0,

10.22.63 ∫0∞Jμ⁡(a⁢t)⁢Jμ−1⁡(b⁢t)⁢dt={bμ−1⁢a−μ,0<b<a,(2⁢b)−1,b=a(>0),0,0<a<b.

When n=0,1,2,… and ℜ⁡μ>−n−1,

10.22.64 ∫0∞Jμ+2⁢n+1⁡(a⁢t)⁢Jμ⁡(b⁢t)⁢dt={bμ⁢Γ⁡(μ+n+1)aμ+1⁢n!⁢𝐅⁡(−n,μ+n+1;μ+1;b2a2),0<b<a,(−1)n/(2⁢a),b=a(>0),0,0<a<b.
10.22.65 ∫0∞J0⁡(a⁢t)⁢(J0⁡(b⁢t)−J0⁡(c⁢t))⁢dtt={0,0≤b<a,0<c≤a,ln⁡(c/a),0≤b<a≤c.

Other Double Products

In (10.22.66)–(10.22.70) a,b,c are positive constants.

10.22.66 ∫0∞e−a⁢t⁢Jν⁡(b⁢t)⁢Jν⁡(c⁢t)⁢dt =1π⁢(b⁢c)12⁢Qν−12⁡(a2+b2+c22⁢b⁢c),
ℜ⁡ν>−12.
10.22.67 ∫0∞t⁢exp⁡(−p2⁢t2)⁢Jν⁡(a⁢t)⁢Jν⁡(b⁢t)⁢dt =12⁢p2⁢exp⁡(−a2+b24⁢p2)⁢Iν⁡(a⁢b2⁢p2),
ℜ⁡ν>−1,ℜ⁡(p2)>0.
10.22.68 ∫0∞t⁢exp⁡(−p2⁢t2)⁢J0⁡(a⁢t)⁢Y0⁡(a⁢t)⁢dt =−12⁢π⁢p2⁢exp⁡(−a22⁢p2)⁢K0⁡(a22⁢p2),
ℜ⁡(p2)>0.

For the associated Legendre function Q see §14.3(ii) with μ=0. For I and K see §10.25(ii).

10.22.69 ∫0∞Jν⁡(a⁢t)⁢Jν⁡(b⁢t)⁢t⁢dtt2−z2 ={12⁢π⁢i⁢Jν⁡(b⁢z)⁢Hν(1)⁡(a⁢z),a>b12⁢π⁢i⁢Jν⁡(a⁢z)⁢Hν(1)⁡(b⁢z),b>a},
ℜ⁡ν>−1,ℑ⁡z>0.
10.22.70 ∫0∞Yν⁡(a⁢t)⁢Jν+1⁡(b⁢t)⁢t⁢dtt2−z2 =12⁢π⁢Jν+1⁡(b⁢z)⁢Hν(1)⁡(a⁢z),
a≥b>0, ℜ⁡ν>−32,ℑ⁡z>0.

Equation (10.22.70) also remains valid if the order ν+1 of the J functions on both sides is replaced by ν+2⁢n−3, n=1,2,…, and the constraint ℜ⁡ν>−32 is replaced by ℜ⁡ν>−n+12.

See also §1.17(ii) for an integral representation of the Dirac delta in terms of a product of Bessel functions.

Triple Products

In (10.22.71) and (10.22.72) a,b,c are positive constants.

10.22.71 ∫0∞Jμ⁡(a⁢t)⁢Jν⁡(b⁢t)⁢Jν⁡(c⁢t)⁢t1−μ⁢dt =(b⁢c)μ−1⁢(sin⁡ϕ)μ−12(2⁢π)12⁢aμ⁢𝖯ν−1212−μ⁡(cos⁡ϕ),
ℜ⁡μ>−12,ℜ⁡ν>−1,|b−c|<a<b+c,cos⁡ϕ=(b2+c2−a2)/(2⁢b⁢c).
10.22.72 ∫0∞Jμ⁡(a⁢t)⁢Jν⁡(b⁢t)⁢Jν⁡(c⁢t)⁢t1−μ⁢dt =(b⁢c)μ−1⁢sin⁡((μ−ν)⁢π)⁢(sinh⁡χ)μ−12(12⁢π3)12⁢aμ⁢e(μ−12)⁢i⁢π⁢Qν−1212−μ⁡(cosh⁡χ),
ℜ⁡μ>−12,ℜ⁡ν>−1,a>b+c,cosh⁡χ=(a2−b2−c2)/(2⁢b⁢c).

For the Ferrers function 𝖯 and the associated Legendre function Q, see §§14.3(i) and 14.3(ii), respectively.

In (10.22.74) and (10.22.75), a,b,c are positive constants and

10.22.73 A =s⁢(s−a)⁢(s−b)⁢(s−c),
s =12⁢(a+b+c).

(Thus if a,b,c are the sides of a triangle, then A12 is the area of the triangle.)

If ℜ⁡ν>−12, then

10.22.74 ∫0∞Jν⁡(a⁢t)⁢Jν⁡(b⁢t)⁢Jν⁡(c⁢t)⁢t1−ν⁢dt ={2ν−1⁢Aν−12π12⁢(a⁢b⁢c)ν⁢Γ⁡(ν+12),A>0,0,A≤0.
If |ν|<12, then
10.22.75 ∫0∞Yν⁡(a⁢t)⁢Jν⁡(b⁢t)⁢Jν⁡(c⁢t)⁢t1+ν⁢dt ={−(a⁢b⁢c)ν⁢(−A)−ν−12π12⁢2ν+1⁢Γ⁡(12−ν),0<a<|b−c|,0,|b−c|<a<b+c,(a⁢b⁢c)ν⁢(−A)−ν−12π12⁢2ν+1⁢Γ⁡(12−ν),a>b+c.

Additional infinite integrals over the product of three Bessel functions (including modified Bessel functions) are given in Gervois and Navelet (1984, 1985a, 1985b, 1986a, 1986b).

§10.22(v) Hankel Transform

The Hankel transform (or Bessel transform) of a function f⁡(x) is defined as

10.22.76 g⁡(y)=∫0∞f⁡(x)⁢Jν⁡(x⁢y)⁢(x⁢y)12⁢dx.

Hankel’s inversion theorem is given by

10.22.77 f⁡(y)=∫0∞g⁡(x)⁢Jν⁡(x⁢y)⁢(x⁢y)12⁢dx.

Sufficient conditions for the validity of (10.22.77) are that ∫0∞|f⁡(x)|⁢dx<∞ when ν≥−12, or that ∫0∞|f⁡(x)|⁢dx<∞ and ∫01xν+12⁢|f⁡(x)|⁢dx<∞ when −1<ν<−12; see Titchmarsh (1986a, Theorem 135, Chapter 8) and Akhiezer (1988, p. 62).

For asymptotic expansions of Hankel transforms see Wong (1976, 1977), Frenzen and Wong (1985a) and Galapon and Martinez (2014).

For collections of Hankel transforms see Erdélyi et al. (1954b, Chapter 8) and Oberhettinger (1972).

The following two formulas are generalizations of the Hankel transform. These are examples of the self-adjoint extensions and the Weyl alternatives of §1.18(ix).

10.22.78 f⁡(x)=∫0∞(x⁢t)12⁢Jν⁡(x⁢t)⁢Yν⁡(a⁢t)−Yν⁡(x⁢t)⁢Jν⁡(a⁢t)Jν2⁡(a⁢t)+Yν2⁡(a⁢t)×∫a∞(y⁢t)12⁢(Jν⁡(y⁢t)⁢Yν⁡(a⁢t)−Yν⁡(y⁢t)⁢Jν⁡(a⁢t))⁢f⁡(y)⁢dy⁢dt,
a>0.

This is the Weber transform. A sufficient condition for the validity is ∫a∞|f⁡(y)|⁢dy<∞.

10.22.79 f⁡(x)=∫0∞(x⁢t)12⁢c⁢Jν⁡(x⁢t)+t2⁢ν⁢J−ν⁡(x⁢t)c2+2⁢c⁢cos⁡(ν⁢π)⁢t2⁢ν+t4⁢ν×∫0∞(y⁢t)12⁢(c⁢Jν⁡(y⁢t)+t2⁢ν⁢J−ν⁡(y⁢t))⁢f⁡(y)⁢dy⁢dt,
0<ν<1,c>0.

Sufficient conditions for the validity of (10.22.79) are that ∫0∞|f⁡(x)|⁢dx<∞ when 0<ν≤12, or that ∫0∞|f⁡(x)|⁢dx<∞ and ∫01x12−ν⁢|f⁡(x)|⁢dx<∞ when 12<ν<1; see Titchmarsh (1962a, pp. 88–90).

§10.22(vi) Compendia

For collections of integrals of the functions Jν⁡(z), Yν⁡(z), Hν(1)⁡(z), and Hν(2)⁡(z), including integrals with respect to the order, see Andrews et al. (1999, pp. 216–225), Apelblat (1983, §12), Erdélyi et al. (1953b, §§7.7.1–7.7.7 and 7.14–7.14.2), Erdélyi et al. (1954a, b), Gradshteyn and Ryzhik (2015, §§5.5 and 6.5–6.7), Gröbner and Hofreiter (1950, pp. 196–204), Luke (1962), Magnus et al. (1966, §3.8), Marichev (1983, pp. 191–216), Oberhettinger (1974, §§1.10 and 2.7), Oberhettinger (1990, §§1.13–1.16 and 2.13–2.16), Oberhettinger and Badii (1973, §§1.14 and 2.12), Okui (1974, 1975), Prudnikov et al. (1986b, §§1.8–1.10, 2.12–2.14, 3.2.4–3.2.7, 3.3.2, and 3.4.1), Prudnikov et al. (1992a, §§3.12–3.14), Prudnikov et al. (1992b, §§3.12–3.14), Watson (1944, Chapters 5, 12, 13, and 14), and Wheelon (1968).