User Ludwig

29 votes

15 answers

4k views

Unconventional examples of mathematical modelling

asked Aug 15, 2019 at 5:33

18 votes

4 answers

1k views

A seemingly simple inequality

asked Jan 15, 2017 at 9:05

16 votes

2 answers

504 views

The number of 0-1 normal matrices

asked May 4, 2019 at 16:58

13 votes

2 answers

1k views

A log inequality for positive definite trace-one matrices

asked Mar 13, 2016 at 20:50

12 votes

2 answers

800 views

A (linear) optimization problem subject to (linear) matrix inequality constraints

asked Sep 28, 2018 at 0:10

9 votes

2 answers

685 views

A trace-constrained maximization problem in the cone of positive definite matrices

asked Sep 4, 2018 at 2:37

9 votes

1 answer

847 views

Maximizing a ratio of determinants

asked May 19, 2017 at 7:08

8 votes

1 answer

906 views

A generalized log inequality for positive definite trace-one matrices

asked Jan 28, 2017 at 10:31

8 votes

0 answers

378 views

A limiting sequence of positive definite matrices

asked Dec 23, 2018 at 2:03

7 votes

1 answer

930 views

(In)stability of a two-dimensional dynamical system

asked Jul 14, 2018 at 19:04

7 votes

3 answers

513 views

Trace of a nonlinear matrix equation (cont'd)

asked Sep 13, 2016 at 14:49

6 votes

1 answer

587 views

On a trace condition for positive definite $2\times 2$ block matrices

asked Sep 18, 2016 at 15:43

6 votes

1 answer

374 views

Asymptotic behavior of a certain trigonometric partial sum

asked Oct 30, 2018 at 0:21

5 votes

1 answer

368 views

$(AB)^+\approx B^+A^+$ for $B$ "fat" enough?

asked Jan 2, 2019 at 12:58

5 votes

2 answers

251 views

Eigenvalue density of a symmetric tridiagonal matrix

asked Oct 25, 2018 at 18:58

5 votes

1 answer

155 views

Finding a particular matrix factor

asked Jun 24, 2018 at 4:12

5 votes

2 answers

828 views

Conditions for convergence to non-isolated fixed points

asked Jul 16, 2016 at 14:43

5 votes

1 answer

401 views

Trace of a nonlinear matrix equation

asked Sep 12, 2016 at 12:36

4 votes

1 answer

153 views

Perturbing the constant term of a polynomial and implications to stability

asked Dec 6, 2014 at 18:52

4 votes

0 answers

231 views

On contractive properties of a nonlinear matrix algorithm

asked Dec 27, 2015 at 13:28

4 votes

1 answer

378 views

On the solvability of a matrix equation

asked Jan 17, 2017 at 16:53

4 votes

1 answer

225 views

$\mathrm{diag}\left[(A+D)^{-1}\right] \ge \left[\mathrm{diag}(A)+D\right]^{-1}$?

asked May 19, 2017 at 15:11

4 votes

0 answers

82 views

Non-singularity of a series of matrices

asked Nov 30, 2017 at 16:29

4 votes

1 answer

407 views

On a vanishing integral inner product

asked Jan 5, 2018 at 9:48

4 votes

0 answers

284 views

Maximizing a certain eigenvalue ratio

asked May 8, 2018 at 21:15

4 votes

0 answers

249 views

Is every stable matrix orthogonally similar to a $D$-skew-symmetric matrix?

asked Oct 14, 2018 at 1:27

4 votes

3 answers

239 views

Properties of matrix $X=\left[\frac{1}{1-\bar\alpha_i \alpha_j}\right]_{ij}$

asked Jul 31, 2020 at 10:31

4 votes

1 answer

265 views

Bounds on discrepancy metric of product measures

asked Aug 8, 2022 at 20:24

3 votes

0 answers

252 views

On the existence of fixed points of a matrix iteration

asked Dec 14, 2018 at 16:38

3 votes

0 answers

178 views

On a matrix inequality based on the Schur-Horn theorem

asked Sep 30, 2018 at 17:41

Stack Exchange Network

63 Questions

Unconventional examples of mathematical modelling

A seemingly simple inequality

The number of 0-1 normal matrices

A log inequality for positive definite trace-one matrices

A (linear) optimization problem subject to (linear) matrix inequality constraints

A trace-constrained maximization problem in the cone of positive definite matrices

Maximizing a ratio of determinants

A generalized log inequality for positive definite trace-one matrices

A limiting sequence of positive definite matrices

(In)stability of a two-dimensional dynamical system

Trace of a nonlinear matrix equation (cont'd)

On a trace condition for positive definite $2\times 2$ block matrices

Asymptotic behavior of a certain trigonometric partial sum

$(AB)^+\approx B^+A^+$ for $B$ "fat" enough?

Eigenvalue density of a symmetric tridiagonal matrix

Finding a particular matrix factor

Conditions for convergence to non-isolated fixed points

Trace of a nonlinear matrix equation

Perturbing the constant term of a polynomial and implications to stability

On contractive properties of a nonlinear matrix algorithm

On the solvability of a matrix equation

$\mathrm{diag}\left[(A+D)^{-1}\right] \ge \left[\mathrm{diag}(A)+D\right]^{-1}$?

Non-singularity of a series of matrices

On a vanishing integral inner product

Maximizing a certain eigenvalue ratio

Is every stable matrix orthogonally similar to a $D$-skew-symmetric matrix?

Properties of matrix $X=\left[\frac{1}{1-\bar\alpha_i \alpha_j}\right]_{ij}$

Bounds on discrepancy metric of product measures

On the existence of fixed points of a matrix iteration

On a matrix inequality based on the Schur-Horn theorem