# Quick notation question (QFT)

1. Nov 21, 2006

### alfredblase

$$\delta^{\left(d\right)}\left(\b{q}-\b{q}\prime \right)$$

from Quantum Field theory and Critical Phenomena by Justin.. (the text covers QFT from a statistical view)

Question: what does the d in brackets mean/do ?

Thanks =)

2. Nov 21, 2006

### inha

this is mainly a quess but I think it could be the dimension of the delta function ie if d=3 the the q-vectors are 3 component vectors. I think I've seen such notation used somewhere.

3. Nov 22, 2006

### dextercioby

I've seen it in BRST, so i also think it may mean the dimension of space(time).

Daniel.

4. Nov 22, 2006

### alfredblase

lol can't be bothered with latex at the mo, but yeah I asked someone in my office and they said it meant that function multiplied together d times but in terms of the dimensional components

Last edited: Nov 22, 2006