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Ludwig
  • Member for 7 years, 5 months
  • Last seen this week
  • Berlin, Germany
27 votes
15 answers
4k views

Unconventional examples of mathematical modelling

18 votes
4 answers
1k views

A seemingly simple inequality

16 votes
2 answers
450 views

The number of 0-1 normal matrices

13 votes
2 answers
1k views

A log inequality for positive definite trace-one matrices

11 votes
2 answers
599 views

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

9 votes
2 answers
494 views

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

9 votes
1 answer
645 views

Maximizing a ratio of determinants

8 votes
1 answer
798 views

A generalized log inequality for positive definite trace-one matrices

8 votes
0 answers
263 views

A limiting sequence of positive definite matrices

7 votes
1 answer
865 views

(In)stability of a two-dimensional dynamical system

7 votes
3 answers
502 views

Trace of a nonlinear matrix equation (cont'd)

6 votes
1 answer
408 views

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

6 votes
1 answer
357 views

Asymptotic behavior of a certain trigonometric partial sum

5 votes
1 answer
345 views

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

5 votes
1 answer
140 views

Finding a particular matrix factor

5 votes
1 answer
356 views

Trace of a nonlinear matrix equation

4 votes
2 answers
627 views

Conditions for convergence to non-isolated fixed points

4 votes
1 answer
148 views

Perturbing the constant term of a polynomial and implications to stability

4 votes
0 answers
220 views

On contractive properties of a nonlinear matrix algorithm

4 votes
1 answer
320 views

On the solvability of a matrix equation

4 votes
1 answer
201 views

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

4 votes
0 answers
80 views

Non-singularity of a series of matrices

4 votes
1 answer
368 views

On a vanishing integral inner product

4 votes
0 answers
217 views

Maximizing a certain eigenvalue ratio

4 votes
0 answers
216 views

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

4 votes
2 answers
179 views

Eigenvalue density of a symmetric tridiagonal matrix

4 votes
3 answers
208 views

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

3 votes
0 answers
152 views

On a matrix inequality based on the Schur-Horn theorem

3 votes
0 answers
239 views

On the existence of fixed points of a matrix iteration

3 votes
1 answer
274 views

Bounding a series of nested integrals