Let all the elements of the fourth-order matrix a be 1, then the nonzero eigenvalue of a is 1

Let all the elements of the fourth-order matrix a be 1, then the nonzero eigenvalue of a is 1

four
det[
1-a, 1, 1, 1;
1, 1-a, 1, 1;
1, 1, 1-a,1;
1, 1, 1, 1-a
]
=det[
-a, 0, 0, a;
0, -a, 0, a;
0, 0, -a, a;
1, 1, 1, 1-a;
]
=a^3*det[
-1, 0, 0, 1;
0, -1, 0, 1;
0, 0, -1, 1;
1, 1, 1, 1-a;
]
=a^3*det[
-1,0,0,1;
0,-1,0,1;
0,0,-1,1;
0,0,0, 4-a;
]
=a^3(a-4)
Nonzero eigenvalue = 4

Elden Ring Premiere

RELATED INFORMATIONS