Possible Duplicate:
How to look up a symbol?
How can I get the "hooked" form of lowercase tau (see below) to show in posts in SE (Math, Theoretical CS, etc.)?

P.S. I tried the "obvious" \vartau, but no dice.
Possible Duplicate:
How to look up a symbol?
How can I get the "hooked" form of lowercase tau (see below) to show in posts in SE (Math, Theoretical CS, etc.)?

P.S. I tried the "obvious" \vartau, but no dice.
For such concerns, have a look at Detexify², which will try to recognice a symbol you drew:

As you can see, it totally agrees with Mico.
You can also have a look at the following question: How to look up a symbol? It deals with the common problem of finding the code for a certain symbol.
You're so close. Try loading the upgreek package and then typing \uptau.
upgreek package. However, the \uptau symbol is upright. Is it somehow possible to get the italicized version of the same symbol? I don't want the regular \tau.
– TRK
Jan 22 '22 at 19:34
\uptauand\tauup, both of which require additional fonts/packages which MathJax don't support natively. – Werner Jan 06 '12 at 06:08