# Questions tagged [matrices]

Questions where the notion matrix has an important or crucial role (for the latter, note the tag matrix-theory for potential use). Matrices appear in various parts of mathematics, and this tag is typically combined with other tags to make the general subject clear, such as an appropriate top-level tag ra.rings-and-algebras, co.combinatorics, etc. and other tags that might be applicable. There are also several more specialized tags concerning matrices.

**2**

**1**answer

### Maximum rank in a class of $0\,$-$1$ partitioned matrices satisfying combinatorial constraints

**-4**

**1**answer

### How to calculate $y^T \mbox{diag}(A^T B A) \,y$ efficiently? [closed]

**7**

**1**answer

### Lower bound on the eigenvalues of the Laplacian

**3**

**1**answer

### « Generalized simultaneous diagonalization » of a pair of symmetric, non-commuting, positive semi-definite matrices

**2**

**0**answers

### Points on Sphere whose image, under symmetric positive definite matrix, is contained in cube

**14**

**5**answers

### Matrix trace & norm [closed]

**2**

**1**answer

### How the eigenvalues change when a Hermitian matrix is left multiplied and right multiplied by a diagonal matrix?

**0**

**0**answers

### Upper bound on matrix perturbation such that all eigenvalues lie within the unit circle

**0**

**0**answers

### On fixed dimension integer programming complexity when LLL is perfect

**2**

**2**answers

### Regarding minimal elementary generators for $GL(n, \mathbb{Z})$

**1**

**0**answers

### specific sequence of matrices making a strange ratio of matrix norms diverging

**0**

**1**answer

### What is special about 2 + $\sqrt{3}$?

**2**

**0**answers

### Representable integer matrices

**5**

**1**answer

### Rational map given by pfaffians

**11**

**2**answers

### Sum-regular $\{0,1\}$-matrices

**0**

**0**answers

### Complex symmetric matrices in a conjugacy class of SU(N)

**5**

**3**answers

### How many $40$-vertex cubic bipartite graphs have determinant $\pm 3$?

**1**

**2**answers

### Low-rank solution of generalized Sylvester equation

**0**

**0**answers

### Convexity of the Frobenius norm of the product of matrices

**6**

**0**answers

### A rank inequality

**2**

**0**answers

### How to prove this matrix is idempotent and that it obeys a telescoping identity

**0**

**0**answers

### Norm inequalities for operator valued matrices

**8**

**5**answers

### Nearest matrix orthogonally similar to a given matrix

**4**

**1**answer

### A Handbook of Matrix Factorizations

**21**

**6**answers

### What are the possible eigenvalues of these matrices?

**0**

**0**answers

### Number of full-rank matrices over a finite field with a full weight

**3**

**1**answer

### Eigenvalues and eigenvectors of tridiagonal matrices

**2**

**0**answers

### Non singularity of a generalised Vandermonde matrix through Hadamard product

**3**

**2**answers

### Proving that a matrix is positive semidefinite

**8**

**2**answers

### Matrix exponential, containing a thermal state

**9**

**1**answer

### Regular $p$-norm of a matrix

**0**

**0**answers

### Eigenvalues of a specific Hankel matrix

**0**

**1**answer

### $A_{n \times m} D_{m \times m} A^T_{m \times n} + \alpha I_{n \times n}$

**5**

**0**answers

### Resultant of a binomial and a trinomial

**2**

**1**answer

### Properties of Zero Line-Sum Matrices

**5**

**1**answer

### On faces of convex sets of positive semidefinite matrices

**3**

**1**answer

### A matrix monotonicity question

**2**

**1**answer

### Quadratic matrix equation for $X\in \mathbb{C}^{ n\times p}$ with Hermitian parameters

**7**

**3**answers

### Checking positive semi-definiteness of integer matrix

**0**

**0**answers

### Gradient of the trace of the logarithm of a product

**3**

**2**answers

### If $S$ is a nonsingular symmetric matrix over a number field and $D_k$ is its principal minor of order $k$, is $\frac{D_k}{D_{k-1}} > 0$ always true?

**3**

**1**answer

### Bounds for eigenvalues of block matrix

**11**

**1**answer

### Determinant of identity matrix plus Hilbert matrix

**24**

**2**answers

### Is this proof of Perron's theorem correct, and if so is it original?

**0**

**1**answer

### Does stability imply that the logarithmic norm is negative?

**8**

**1**answer

### Gaussian integrals over the space of symmetric matrices

**2**

**2**answers

### Inverse of particular lower triangular matrix

**3**

**0**answers

### Maximum number of negative entries in a matrix with positive diagonal and given rank

**4**

**0**answers

### A Toeplitz variant of the Hilbert matrix

**3**

**1**answer