How Do Community Members Feel About Our Research?

[Monkeyfry180]

Sounds great thank you

 

[Simon_Tyler]

The 2x2 case is easy (for the general case, see e.g. www-math.mit.edu/~dav/genlin.pdf).

You want to find z such that zg=gz for all g in G.
Let z = {{z11,z12},{z21,z22}}
If you choose g = {{0,1},{1,0}} then you find that
z11 = z22 and z12 = z21
If you choose g = {{0,1},{-1,0}} then you get
z11 = z22 and z12 = -z21
Thus z12 = z21 = 0 and z must be a nonzero (real) http://en.wikipedia.org/wiki/Scalar_matrix" .

 

[HallsofIvy]

I would appreciate it if people would NOT erase their post after it has been answered. Other people use these posts to learn and erasing the original question makes that very difficult.

 

[Simon_Tyler]

@HallsofIvy.
I was just thinking the same thing. Maybe if there was an option to look a the history of an edited post then it wouldn't be so much of an issue?