Determinants and Their Applications in Mathematical Physics

(Chris Devlin) #1

158 4. Particular Determinants


Hn=|Si+j− 2 |n=λnx

n(n+1)/ 2
,

Jn=|Ai+j− 2 |n=λnx

n(n−1)/ 2
,

where


λn=

[

1! 2! 3!···(n−1)!]

2
.

The following proofs differ from the originals in some respects.

Proof. It is proved using a slightly different notation in Theorem 4.28


in Section 4.8.5 on Turanians that


EnGn−En+1Gn− 1 =F

2
n

,

which is equivalent to


En− 1 Gn− 1 −EnGn− 2 =F

2
n− 1

. (4.12.16)

Putx=e
t
in (4.12.5) so that


Dx=e

−t
Dt

Dt=xDx,Dx=


∂x

,etc. (4.12.17)

Also, put


θm(t)=ψm(e

t
)

=



r=1

r

m
e

rt

θ


m(t)=θm+1(t). (4.12.18)

Define the column vectorCj(t) as follows:


Cj(t)=

[

θj(t)θj+1(t)θj+2(t)...

]T

so that


C


j
=Cj+1(t). (4.12.19)

The number of elements inCjis equal to the order of the determinant of


which it is a part, that is,n,n−1, orn−2 in the present context.


Let

Qn(t, τ)=


∣C

0 (τ)C 1 (t)C 2 (t)···Cn− 1 (t)



n

, (4.12.20)

where the argument in the first column isτ and the argument in each of


the other columns ist. Then,


Qn(t, t)=En. (4.12.21)

DifferentiateQnrepeatedly with respect toτ, apply (4.12.19), and put


τ=t.


D

r
τ
{Qn(t, t)}=0, 1 ≤r≤n− 1 , (4.12.22)
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