Why are the eigenvalues of $X'X$ equal to that of $XX'$ when $X$ is a design matrix?
103087
What is the duality relationship between eigensystems of X X' vs X' X?
71604
Why is the determinant of the 0x0 matrix equal 1?
24423
What is the difference between "singular value" and "eigenvalue"?
84626
Why in these matrices are $AB=BA$ not equal? What is the logic behind them?
149916
Minimum eigenvalue and singular value of a square matrix
50384
A matrix and its transpose have the same set of eigenvalues/other version: $A$ and $A^T$ have the same spectrum
129977
Prove that $\lambda_1^2$, $\lambda_1\lambda_2$ and $\lambda_2^2$ are eigenvalues of matrix $A$
104293
How to prove "eigenvalues of polynomial of matrix $A$ = polynomial of eigenvalues of matrix $A$ "
125569
Prove that the eigenvalues of a real symmetric matrix are real
126337
Eigenvalues in orthogonal matrices
93325
Difference In Eigenvectors
149629
The Eigenvalues of a block matrix
123679
General Information about Eigenvalues for an 3x3 symmetric matrix
67588
Why does $|e^{ix}|^2 = 1$?
115467
Eigenvalues of Householder matrix
52946
If $X$ is an orthogonal matrix, why does $X^TX = I$?
102317
Is there a geometrical interpretation to the notion of eigenvector and eigenvalues?