# Srednicki equation 5.10

In equation 5.10, second line srednicki uses the same definition as eq 5.6, while 5.6 is time independent $$a_1^{\dagger}(k)$$ and in 5.10 we have to use the new time dependent $$a_1^{\dagger}(t)$$ . Why dont we have a new $$a_1^{\dagger}(t)$$, which say explicitly depends on t ?

I will be glad if someone can explain :)

just before eq 5-8:

One complication is that a†(k) will no longer be time independent, and so a†1, eq. (5.6),
becomes time dependent as well.

thankyou for pointing out, I should read between the lines..

It will be very kind if you can also explain how to understand paragraph starting with "We would like ........ is not zero" on page 39, after equation 5.17

try to work it out, i have no idea where you are stuck

I am working on it, thanks for you help :)