How can I write a matrix element of the group -LSB- math -RSB- SU -LRB- 2 -RRB- \ times SU -LRB- 2 -RRB- -LSB- / math -RSB- for the -LSB- math -RSB- -LRB- 0 , 1/2 -RRB- -LSB- / math -RSB- representation of the Lorentz group -LSB- math -RSB- SO -LRB- 1,3 -RRB- -LSB- / math -RSB- ?
What is the difference of the sound quality between listening through an audio interface or listening straight from the computer ?