Recent content by majon

I was asking because I was reading a document where the author deals with 3 equations and 3 unknown parameters, each equation has quadratic dependence on each of the 3 parameters. Then the author says: with these three equations and three parameters we can reduce the equations to two second...

Say I have a system of equations of the following form: a_1 A^2 + b_1 B^2 + c_1 C^2 + d_1 = f_1 a_2 A^2 + b_2 B^2 + c_2 C^2 + d_2 = f_2 a_3 A^2 + b_3 B^2 + c_3 C^2 + d_3 = f_3 Where a,b,c,d,f are coefficients, and A,B and C are unknown variables. 1. Can we write them in terms of two variables...

Thanks for your reply Hurkyl. The entries are complex variables, I'll edit my question. And I meant to use the dagger (conjugate transpose) because this form of terms has a specific meaning where I'm using it.

I have a quick question. Say we have the following matrices, A = \begin{pmatrix} a \\ b \end{pmatrix} A^\dagger = \begin{pmatrix} a & b \end{pmatrix} B = \begin{pmatrix} \alpha & \beta \\ \gamma & \delta \end{pmatrix} where the entries can be complex. Now is the following...

Bill_K, I don't think it's a mistake, I think they put it there to indicate something I don't understand. Thanks you for your comments tom.stoer, many thanks for stating the difference between the two expressions, and for mentioning the papers. I shall read them and see what can get out of them

I know what gauge invariance is, but I'm not sure what gauge covariance is. Is it that a given field has a gauge covariant derivative? And under which circumstances do we get a field that is gauge invariant but not gauge covariant? And I would appreciate an example (other than the one...

This link might help: www . phi . duke . edu/courses/217/MottScatteringReport/node8.html