Hermite transform explained

Hn(x)

as kernels of the transform.

The Hermite transform

H\{F(x)\}\equivfH(n)

of a function

F(x)

isH\ \equiv f_H(n) = \int_^\infty e^ \ H_n(x)\ F(x) \ dx

The inverse Hermite transform

H-1\{fH(n)\}

is given byH^\ \equiv F(x) = \sum_^\infty \frac f_H(n) H_n(x)

Some Hermite transform pairs

F(x)

fH(n)

xm

\begin{cases}

m!\sqrt{\pi
}{2

m-n\left(

m-n
2

\right)!},&(m-n)evenand\geq0\\ 0,&otherwise\end{cases}

eax

\sqrt\pian

a2/4
e

2xt-t2
e

,

t<\frac\,

\sqrt\pi(2t)n

Hm(x)

\sqrt\pi2nn!\deltanm

2H
x
m(x)

2nn!\sqrt{\pi}\begin{cases}1,&n=m+2\\ \left(n+

1
2

\right),&n=m\\ (n+1)(n+2),&n=m-2\\ 0,&otherwise\end{cases}

-x2
e

Hm(x)

\left(-1\right)p-m2p-1/2\Gamma(p+1/2),m+n=2p,p\inZ

2(x)
H
m

\begin{cases} 2m+n/2\sqrt\pi\binomm{n/2}

m!n!
(n/2)!

,&nevenand\leq2m\\ 0,&otherwise \end{cases}

[1]

Hm(x)Hp(x)

\begin{cases}

2k\sqrt\pim!n!p!
(k-m)!(k-n)!(k-p)!

,&n+m+p=2k,k\inZ;

m-p\leq n\leq m+p\\ 0, & \text \end\,[2]

Hn+p+q(x)Hp(x)Hq(x)

\sqrt\pi2n+p+q(n+p+q)!

dm
dxm

F(x)

fH(n+m)

xdm
dxm

F(x)

nf
H(n+m-1)+1
2

fH(n+m+1)

x2
e
d
dx
-x2
\left[e
d
dx

F(x)\right]

-2nfH(n)

F(x-x0)

infty
\sqrt{\pi}\sum
k=0
k
(-x
0)
k!

fH(n+k)

F(x)*G(x)

\sqrt\pi(-1)n\left[22n+1\Gamma\left(n+

3
2

\right)\right]-1fH(n)gH(n)

[3]
z2
e

\sin(xz),

z<\frac 12\ \,

\begin{cases} \sqrt\pi

\lfloorn\rfloor
2
(-1)

(2z)n,&nodd\\ 0,&neven \end{cases}

(1-z2)-1/2\exp\left[

2xyz-(x2+y2)z2
(1-z2)

\right]

\sqrt\piznHn(y)

[4] [5]
Hm(y)Hm+1(x)-Hm(x)Hm+1(y)
2m+1m!(x-y)

\begin{cases}\sqrt{\pi}Hn(y)&n\leqm\\ 0&n>m \end{cases}

Notes and References

  1. Feldheim . Ervin . 1938 . Quelques nouvelles relations pour les polynomes d'Hermite . Journal of the London Mathematical Society . fr . s1-13 . 22–29 . 10.1112/jlms/s1-13.1.22.
  2. Bailey . W. N. . On Hermite polynomials and associated Legendre functions . Journal of the London Mathematical Society . 4 . 1939 . 281–286 . s1-14 . 10.1112/jlms/s1-14.4.281.
  3. Glaeske . Hans-Jürgen . On a convolution structure of a generalized Hermite transformation . Serdica Bulgariacae Mathematicae Publicationes . 9 . 2 . 1983 . 223–229 .
  4. , 10.13 (22).
  5. . See p. 174, eq. (18) and p. 173, eq. (13).