# 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.

**3**

**1**answer

### Matrix inequality : trace of exponential of Hermitian matrix

**0**

**1**answer

### Isomorphism between two groups [closed]

**4**

**0**answers

### Characterization of “PSD-Squared” Matrices

**0**

**0**answers

### Is the SVD optimal (by Eckart Young theorem) because maximal data variance is captured from both the column and row space?

**-1**

**0**answers

### What is the normal subgroup generated by nonsingular, positive definite matrices? [closed]

**1**

**1**answer

### Integrality certification for product of two matrices $A B^{-1}$

**6**

**0**answers

### An integral Jacobson-Morozov theorem?

**1**

**1**answer

### Do there exist graphs whose adjacency matrix is positive semi-definite? [closed]

**-1**

**0**answers

### “euler form” of a unitary matrix? [closed]

**0**

**0**answers

### trace expressions for matrix quadratic forms [migrated]

**1**

**0**answers

### Phase angles of a complex eigenvector

**27**

**0**answers

### Sum over 0-1 matrices

**12**

**0**answers

### Combinatorial proof of invertibility of a symmetric matrix associated to the ring of matrices over a finite field

**6**

**2**answers

### Characteristic polynomial of checker matrix

**4**

**0**answers

### Inequalities for trace/eigenvalues of product of multiple 2x2 matrices

**4**

**1**answer

### Neighborhood of an orthogonal matrix

**0**

**0**answers

### pseudo-inverse of short fat matrix

**4**

**1**answer

### Simple way to calculate the eigenvalues of a $2 \times 2 \times 2$ tensor

**-2**

**0**answers

### Can we use modified Cholesky's decomposition for solving linear equations?

**3**

**1**answer

### An orthogonal matrix that satisfies a property must be a permutation matrix

**2**

**1**answer

### Average number of elements of a subset S of a matrix A after inducing the rows and columns of m randomly selected elements from subset S

**1**

**0**answers

### Eigenvalues of symmetric tridiagonal matrices with identical off diagonal elements

**4**

**0**answers

### Number of elements in $\mathrm{GL}(n,p)$ with maximal order

**8**

**0**answers

### Membership problem in general linear group

**1**

**0**answers

### Diagonally similar to submatrix of orthogonal matrix

**1**

**0**answers

### Fastest way to calculate the eigenvalues of a product of two Toeplitz matrices

**2**

**1**answer

### Max-norm projection of a Hermitian matrix onto the set of positive semidefinite matrices

**3**

**2**answers

### Maximize $l_1$ norm with unitary matrix

**3**

**0**answers

### A non-singularity property for sets of real matrices

**0**

**1**answer

### Conjugacy in the quaternion group

**0**

**0**answers

### “Probability” for a partitioned matrix to be singular

**0**

**0**answers

### Find occurrences of certain matrix inside a matrix

**5**

**1**answer

### How to compute a more general version of Vandermonde / Cauchy double alternant determinant

**1**

**1**answer

### Low-complexity method for sub-matrix inversion

**16**

**2**answers

### How to prove the determinant of a Hilbert-like matrix with parameter is non-zero

**9**

**3**answers

### Subgroup of $\mathrm{GL}_n$ stabilizing linear subspace skew-symmetric matrices

**4**

**1**answer

### Counting adjacency matrices

**3**

**0**answers

### Diffeomorphisms of a “matrix type”

**1**

**0**answers

### Probability of marking at least one row in given matrix

**4**

**1**answer

### Relation of row sums to largest eigenvalue

**0**

**0**answers

### Generalized eigenvectors product

**0**

**2**answers

### Bounding $E[\|\Sigma^{-1/2}(X-\mu)\|_2^3]$ for 2-dimensional Bernoulli

**12**

**2**answers

### Abelianization of general linear group of a polynomial ring

**0**

**1**answer

### Maximize function on rotation matrices [closed]

**5**

**1**answer

### When is the log-permanent concave?

**1**

**1**answer

### A linear algebra question regarding the eigenvalues of the product of a diagonal matrix and a projection matrix

**0**

**1**answer

### The product of non-primitive matrices with zero positions in common

**1**

**0**answers

### Minimum rank of a product of two block diagonal matrices with an arbitrary matrix

**6**

**0**answers

### Computing powers of a special matrix fast

**1**

**0**answers