Determinants and Their Applications in Mathematical Physics

(Chris Devlin) #1

228 5. Further Determinant Theory


identities in whichr=±1 form a dual pair in the sense that one can be


transformed into the other by interchangingHsandhs,s=0, 1 , 2 ,....


Examples.


(n, r)=(2,0):




H 2 H 3

H 1 H 2





=





h 2 h 3

h 1 h 2





;

(n, r)=(3,0):
∣ ∣ ∣ ∣ ∣ ∣
H 3 H 4 H 5

H 2 H 3 H 4

H 1 H 2 H 3

∣ ∣ ∣ ∣ ∣ ∣

=

∣ ∣ ∣ ∣ ∣ ∣

h 3 h 4 h 5

h 2 h 3 h 4

h 1 h 2 h 3

∣ ∣ ∣ ∣ ∣ ∣

;

(n, r)=(2,1):





H 3 H 4

H 2 H 3





=

∣ ∣ ∣ ∣ ∣ ∣

h 2 h 3 h 4

h 1 h 2 h 3

1 h 1 h 2

∣ ∣ ∣ ∣ ∣ ∣

;

(n, r)=(3,−1):
∣ ∣ ∣ ∣ ∣ ∣
H 2 H 3 H 4

H 1 H 2 H 3

1 H 1 H 2

∣ ∣ ∣ ∣ ∣ ∣

=





h 3 h 4

h 2 h 3





.

Conjecture 2.






Hn Hn+1

1 H 1





=

∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣

h 2 h 3 h 4 h 5 ··· hn hn+1

1 h 1 h 2 h 3 ··· hn− 2 hn− 1

1 h 1 h 2 ··· hn− 3 hn− 2

1 h 1 ··· hn− 4 hn− 3

··· ··· ··· ···

1 h 1

∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣ n

.

Note that, in the determinant on the right, there is a break in the sequence


of suffixes from the first row to the second.


The following set of identities suggest the existence of a more general

relation involving determinants in which the sequence of suffixes from one


row to the next or from one column to the next is broken.




H 1 H 3

1 H 2





=





h 1 h 3

1 h 2





,





H 2 H 4

H 1 H 3





=







h 1 h 3 h 4

1 h 2 h 3

h 1 h 2







,





H 3 H 5

H 2 H 4





=

∣ ∣ ∣ ∣ ∣ ∣ ∣

h 1 h 3 h 4 h 5

1 h 2 h 3 h 4

h 1 h 2 h 3

1 h 1 h 2

∣ ∣ ∣ ∣ ∣ ∣ ∣

,
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