Type

D.e.

Solution

Dirichlet Transform of superposition of (discretized) solutions with explanation

Dirichlet Transform of superposition of (discretized) solutions

EULER

x 2 u 2 x 2 + x α u x + β u = 0 (1)

u ( x ) = x λ cos ( μ ln x ) + i x λ sin ( μ ln x ) = x λ exp ( i μ ln x )

D s μ = 1 μ = x λ exp ( i μ ln x ) x λ + i μ = 1 Γ ( s ) M x μ = 1 μ = e λ x exp ( i μ ln e x ) = ( i ) s ς ( s , i λ ) = Φ ( 1 , s , i λ ) i s (99)

Φ is Lerch Transcedent function

( i ) s ς ( s , i λ ) . ς ( s , λ ) = n = 0 n = 1 ( n + λ ) s (100) is the Hurwitz Zeta function as generalization of ς ( s ) with ς ( s , 1 ) = ς ( s ) .

variant modified Hermite

u 2 x 2 ( n 2 + x 1 ) u x + n u = 0 (101)

H ˜ e n ( z ) = U ( n 2 , p + 1 2 n 2 + 1 , z 2 2 ) | z | n

ς ( s ) = 2 s 2 n = 1 n = U ( s 2 , s 2 + 1 , n 2 2 ) 2 s 2 2 s 2 n = 1 n = n s

n = 1 n = D s H ˜ e n ( z ) = ς ( s ) (102)

Confluent hypergeometric

u 2 x 2 + ( c x ) u x a u = 0

u = b 1 F 1 1 ( a ; c ; x ) + b 2 U ( a , c , x ) ;

Special cases:

F 1 1 ( n , n + 1 , x ) ~ Γ ( 1 + n ) Γ ( 1 n ) L n n ( x ) (103)

with L i n ( x ) the associated Laguerre

polynomials [21]

U ( n , n + 1 , x ) ~ x n (107)

U ( n , 2 n , x ) ~ e x 2 π x 1 2 n K n 1 2 ( x 2 ) ~ a n x n (109)

F 1 1 ( n , 2 n , x ) ~ e x 2 π x 4 1 2 n Γ ( n + 1 2 ) I n 1 2 ( x 2 ) n ( n ) n ( 2 n ) x n n ! (113)

; With Γ, Γ(; ;), I, K, resp. the gamma

Γ ( 1 + s ) Γ ( 1 s ) L x x ( n ) = Γ ( 1 + s ) Γ ( 1 s ) 1 s U ( s , s + 1 , n ) ( s ) ! = 1 s U ( s , s + 1 , n ) Γ ( 1 + s ) (104)

1 s Γ ( s + 1 ) ς ( s ) = n = 1 n = F 1 1 ( s , s + 1 , n ) (105), since

ς ( s ) = n = 1 n = U ( s , s + 1 , n ) .

φ ( s ) = n = 1 n = a n n s (110); a n = n = 1 n = k = 0 n a n , k (111) with a n , k OIES A113025. See Table B2.

Γ ( s ) φ ( s ) = Γ ( s ) n = 1 n = a n n s (114); a n = n ( n ) n ( 2 n ) (115);

φ ( s ) = n = 1 n = a n n s (116);

D s n = 1 n = F 1 1 ( n , n + 1 , x ) = 1 s Γ ( s + 1 ) ς ( s ) (106)

D s n = 1 n = U ( n , n + 1 , x ) = ς ( s ) (108)

D s n = 1 n = U ( n , 2 n , x ) = φ ( s ) (112)

φ ( s ) = n = 1 n = a n n s (110)

D s n = 1 n = F 1 1 ( n , 2 n , x ) = φ ( s ) Γ ( s ) (116)

Γ ( s ) φ ( s ) = Γ ( s ) n = 1 n = a n n s (114)

D s n = 1 n = U ( n , 2 n , x ) = φ ( s ) (118)