User adam W - Mathematics Stack Exchange

adam W

Member for 11 years, 2 months
Last seen this week

none
Texas

10 Questions

Score Activity Newest Views

13 votes

7 answers

3k views

Is the square root of a triangular matrix necessarily triangular?

asked Jan 14, 2013 at 1:51

1 vote

0 answers

84 views

Can this sum be shown to be zero? $\sum_k \left[ {m+1} \atop k \right]{ k+n \brace m}(-1)^{m+k} = 0$

asked Mar 28, 2014 at 23:41

5 votes

3 answers

497 views

$\Delta^d m^n =d! \sum_{k} \left[ m \atop k \right] { {k+n} \brace m + d}(-1)^{m+k}$ Is this a new formula?

asked Mar 27, 2014 at 4:15

2 votes

0 answers

280 views

Parametric QR factorization: $\mathbf{D}(\alpha)\mathbf{V}^*$ a diagonal times a constant unitary matrix

asked Nov 11, 2013 at 4:54

11 votes

2 answers

3k views

Is every square traceless matrix unitarily similar to a zero-diagonal matrix?

asked Dec 29, 2012 at 17:48

4 votes

0 answers

120 views

Jacobi's Rotation has two possibilities, why do they both result in same upper triangular magnitude norm?

asked Feb 1, 2013 at 23:10

1 vote

1 answer

71 views

There are $n!$ different unitary similarities that give $L_i \sim L_j$. Or are there more?

asked Jan 14, 2013 at 18:50

-2 votes

4 answers

150 views

Complete instead of Complex, Irregular instead of Imaginary

asked Dec 28, 2012 at 19:29

0 votes

1 answer

209 views

Factoring $\pm \Lambda$ from symmetric $A$ using $LDU$

asked Oct 10, 2012 at 14:35

6 votes

1 answer

2k views

Characterizing a real symmetric matrix $A$ as $A = XX^T - YY^T$

asked Oct 9, 2012 at 12:45