# What does * mean and how is it used

1. May 5, 2007

### chrismariesan

I'm studying hermitian operators and in the equations it keeps using a * after a function i.e. f(x)*
I don't understand what it means and how it's used and why they keep moving it all around the equation....I know it's probably pretty easy and I just missed it in lecture but it's driving me crazy.
pleeeese help!

2. May 5, 2007

### cristo

Staff Emeritus
The * stands for complex conjugatation. So, if f(x) is the wavefunction, then f*(x) is the complex conjugate of the wavefunction.

If you're still unsure, then give an example of it "moves around an equation" and someone can clear it up for you.

3. May 7, 2007

### CaptainQuaser

Complex conjugate means the imaginary part of the function becomes negative, in case you didn't know that.

4. May 7, 2007

### masudr

Just to remove any possible room for error: conjugation changes the sign of the imaginary part, so it could become positive as well (or, indeed, remain zero).