# What does c.c. in equation represent?

1. Aug 20, 2013

### semc

Hi, I am reading up on current injection in semiconductor and in the derivation of the current injection, the equation goes like this

|K|2= ... +Eb(-w) + c.c.

Does anyone knows what does c.c. represent?

2. Aug 20, 2013

### vela

Staff Emeritus
Just a guess, but I'd go with complex conjugate.

3. Aug 20, 2013

### guest1234

This one doesn't look like a complex conjugate, since it's an operation not an additive quantity.
To OP: You just have to give more context, but the chances are that it's explained in the original text.

4. Aug 20, 2013

### vela

Staff Emeritus
I'm not sure how you determined that. After all, there's a plus sign right before "c.c."

5. Aug 20, 2013

### semc

The author is trying to derive the current injection into semiconductor via quantum interference. In his working before this, he is trying to expand a complex equation and the next step is the final result. He did not mention what the c.c. means so I am thinking it might be complex conjugate but I am not sure.

My bad that I did not mention its a complex function :(

6. Aug 21, 2013

### clamtrox

It means complex conjugate of everything that's written down before it. So for example $$\psi_1^* \psi_2 + \psi_2^* \psi_3 + c.c. = \psi_1^* \psi_2 + \psi_1 \psi_2^* + \psi_2^* \psi_3 + \psi_2 \psi_3^*$$
Sometimes you also see "h.c.", which stands for hermitian conjugate.