Row 1st Column bold upper B 2nd Column equals ModifyingAbove Above ModifyingAbove zeta With bar With bar left-parenthesis bold upper F 0 right-parenthesis dot bold upper E plus ModifyingAbove Above ModifyingAbove mu With bar With bar left-parenthesis bold upper F 0 right-parenthesis dot bold upper H comma EndLayout"/>
where represents a time-odd external bias. Under phase conjugation (or time reversal), these constitutive relations become [28]
Expanding the bracketed terms in (2.48), using the identity , where the superscript denotes the transpose operation, and grouping the identical parameter terms, we obtain