User Toni Mhax

6 votes

Accepted

Monotonicity of eigenvalues

answered Mar 16, 2022 at 16:46

6 votes

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Matrices with same eigenvalues

answered May 3, 2023 at 10:39

4 votes

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What is the inverse of a triangular matrix whose nonzero elements are binomial coefficients? What is the closed-form solution to a recursive relation?

answered Dec 18, 2022 at 15:20

4 votes

Are there infinitely many positive integer solutions to $(3+3k+l)^2=m\,(k\,l-k^3-1)$?

answered Jan 23, 2022 at 7:11

3 votes

A real root of a cubic equation for a stationary point

answered Jul 11 at 17:18

1 vote

Determinantal inequality for difference of substochastic matrices

answered Jul 20 at 5:32

1 vote

In arbitrary cyclic polygon then $\sum_{i<j} x_{ij}^\alpha \ge \sum_{i<j} y_{ij}^\alpha $

answered Aug 22 at 17:35

1 vote

Accepted

Generalization of Tucker circle, Conway circle and van Lamoen circle

answered Aug 24 at 16:34

1 vote

A necessary and sufficient condition for three diagonals of a hexagon to be concurrent

answered Sep 24 at 18:46

1 vote

A certain inequality involving square roots of polynomials

answered Dec 4 at 3:29

1 vote

Existence of a specific stochastic matrix

answered Sep 3, 2023 at 15:39

1 vote

An inequality related to matrix trace

answered Sep 14, 2023 at 12:00

1 vote

On the bounds of the sum of the squares of spectral variation of two real symmetric matrices

answered Jan 4, 2023 at 5:41

1 vote

Extend an inequality on matrix norms

answered Jan 4, 2023 at 7:57

1 vote

Finding angle with geometric approach

answered Jan 24, 2023 at 11:31

1 vote

Support of eigenvectors

answered Jun 10, 2022 at 16:47

1 vote

On a generating set of numerical semigroups of multiplicity three

answered Jun 18, 2022 at 14:52

1 vote

Showing a 2-by-2 matrix is a contraction

answered Aug 5, 2022 at 13:04

0 votes

Transforming matrix to off-diagonal form

answered Dec 13, 2022 at 9:24

0 votes

A linear equation problem related to projection

answered Jun 11, 2022 at 17:05

0 votes

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

answered Sep 30, 2018 at 6:08

0 votes

Putnam 2020 inequality for complex numbers in the unit circle

answered Sep 8, 2021 at 14:03

0 votes

An open triangle problem in plane geometry

answered Nov 15, 2021 at 7:41

0 votes

Property of positive semi-definite

answered Feb 7, 2023 at 13:06

0 votes

Eigenvalues and eigenvectors of k-blocks matrix

answered Feb 11, 2023 at 15:54

0 votes

Lower bound on the rank of a graph

answered Mar 10, 2023 at 9:17

0 votes

Sum of squares of $k\times k$ cofactors is $1$ for an orthonormal matrix

answered Jun 17 at 8:42

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27 Answers

Monotonicity of eigenvalues

Matrices with same eigenvalues

What is the inverse of a triangular matrix whose nonzero elements are binomial coefficients? What is the closed-form solution to a recursive relation?

Are there infinitely many positive integer solutions to $(3+3k+l)^2=m\,(k\,l-k^3-1)$?

A real root of a cubic equation for a stationary point

Determinantal inequality for difference of substochastic matrices

In arbitrary cyclic polygon then $\sum_{i<j} x_{ij}^\alpha \ge \sum_{i<j} y_{ij}^\alpha $

Generalization of Tucker circle, Conway circle and van Lamoen circle

A necessary and sufficient condition for three diagonals of a hexagon to be concurrent

A certain inequality involving square roots of polynomials

Existence of a specific stochastic matrix

An inequality related to matrix trace

On the bounds of the sum of the squares of spectral variation of two real symmetric matrices

Extend an inequality on matrix norms

Finding angle with geometric approach

Support of eigenvectors

On a generating set of numerical semigroups of multiplicity three

Showing a 2-by-2 matrix is a contraction

Transforming matrix to off-diagonal form

A linear equation problem related to projection

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

Putnam 2020 inequality for complex numbers in the unit circle

An open triangle problem in plane geometry

Property of positive semi-definite

Eigenvalues and eigenvectors of k-blocks matrix

Lower bound on the rank of a graph

Sum of squares of $k\times k$ cofactors is $1$ for an orthonormal matrix