Can Greek letters be added to Sphinx documents as glossary terms?

I want to add variables that are defined as Greek letters to my glossary in a sphinx document. For example:

.. glossary::

    :math:`{\alpha}`
        Definition for alpha

The goal is to have these variables appear in the document's index. Anyone have experience with this?

Solution

Glossary terms are automatically added to the index. But that does not work for the glossary entry in the question. Sphinx emits this warning: WARNING: invalid single index entry '' (at least it does for me). This feels like a bug.

Here are two workarounds:

Use a substitution
```
|alpha|
   Description of alpha

.. |alpha| replace:: :math:`{\alpha}`
```
The drawback is that it will say "alpha" in the index instead of "α".
Use the actual alpha letter
```
α
   Description of alpha
```
Here α will be an entry in the index under the heading "Symbols".