# Srednicki equation 5.10

1. Mar 23, 2010

### vaibhavtewari

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 :)

2. Mar 23, 2010

### ansgar

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.

3. Mar 23, 2010

### vaibhavtewari

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

4. Mar 23, 2010

### vaibhavtewari

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

5. Mar 23, 2010

### ansgar

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

6. Mar 25, 2010

### vaibhavtewari

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