Determinants and Their Applications in Mathematical Physics

(Chris Devlin) #1

138 4. Particular Determinants


v-Numbers satisfy the identities

n

k=1

vnk

i+k− 1

=1, 1 ≤i≤n, (4.11.3)

vni

n

k=1

vnk

(i+k−1)(k+j−1)

=δij, (4.11.4)

vni

n+i− 1

=−

vn− 1 ,i

n−i

, (4.11.5)

n

i=1

vni=n

2
, (4.11.6)

and are related toKnand its scaled cofactors by


K

ij
n

=

vnivnj

i+j− 1

, (4.11.7)

Kn

n

i=1

vni=(−1)

n(n−1)/ 2

. (4.11.8)


The proofs of these identities are left as exercises for the reader.

4.11.2 Some Determinants with Determinantal Factors


This section is devoted to the factorization of the Hankelian


Bn= detBn,

where


Bn=[bij]n,

bij=

x
2(i+j−1)
−t
2

i+j− 1

, (4.11.9)

and to the function


Gn=

n

j=1

(x

2 j− 1
+t)Bnj, (4.11.10)

which can be expressed as the determinant|gij|nwhose first (n−1) rows


are identical to the first (n−1) rows ofBn. The elements in the last row


are given by


gnj=x

2 j− 1
+t, 1 ≤j≤n.

The analysis employs both matrix and determinantal methods.


Define five matricesKn,Qn,Sn,Hn, andHnas follows:

Kn=

[

1

i+j− 1

]

n

, (4.11.11)
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