6.3 Compact Matrix Formulation of the Generalized BUU Equation
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where Tr ± is the trace over all indices but the last/first pair, e.g.
[Tr + f (x,
p 1 , . . . ,
p n )] s n s
n
:= f s 1 ,...,s n−1 ,s n ;s 1 ,...,s n−1 ,s
n
(x,
p 1 , . . . ,
p n ) ,
(6.3.9)
[Tr − f (x,
p 1 , . . . ,
p n )] s 1 s
1
:= f s 1 ,s 2 ...,s n ;s
1 ,s 2 ...,s n (x,
p 1 , . . . ,
p n ) .
(6.3.10)