# What is the name of this character?

1. Jun 30, 2011

### luitzen

I'm not really sure whether this is the correct place for this question, but I'm gonna ask it anyway.

I've had Latin and Greek classes in high school, but I've never seen this character before. Still, I guess it's an obscure Latin or Greek character, but I don't know it's name. I encountered it in Griffiths where it's used for the momentum of EM-waves.

[PLAIN]http://img8.imageshack.us/img8/9220/unknowncharacter.jpg [Broken]

Last edited by a moderator: May 5, 2017
2. Jun 30, 2011

### Ben Niehoff

It's just a fancy cursive P.

In mathematics, it's usually used to mean the power set.

3. Jun 30, 2011

### TetraEleven

4. Jun 30, 2011

### Redbelly98

Staff Emeritus
That's a Greek lowercase "phi". The OP's character looks quite different to me, as it doesn't have the straight-down tail at the bottom like "phi" does.

5. Jun 30, 2011

### Hurkyl

Staff Emeritus
I think the original poster means the symbol $\wp$.

I confess I only ever recall seeing the symbol used for the [URL [Broken] function[/url] (possibly I've seen it in some fancy cursive script).

Wikipedia has a page on it: Weierstrass p.

A symbol often used for power set is $\mathcal{P}$.
The fancy phi mentinoed is $\varphi$.

Last edited by a moderator: May 5, 2017
6. Jun 30, 2011

### TetraEleven

I figured they probably weren't the same, but I thought I'd try to help anyway.

7. Jun 30, 2011

### Loren Booda

Way to go, Hurkyl.

Last edited by a moderator: May 5, 2017
8. Jul 1, 2011

### luitzen

That's it, so that means it's a Latin P, right?

9. Jul 1, 2011

### Loren Booda

Or German?

10. Jul 4, 2011

### luitzen

No, German doesn't have it's own alphabet, it uses the Latin alphabet. So the question was whether it was a capital rho or pee.

11. Jul 4, 2011

### KrisOhn

It's not from the German alphabet. It's a character created by the German mathematician Karl Weierstrass.

12. Jul 4, 2011

### luitzen

We already established that 3 days ago. German does not have an alphabet. I was asking whether it is a Latin pee or Greek rho.