However, you could use some general collective nouns that would apply, such as:
* A group of mathematicians
* A team of mathematicians
* A society of mathematicians
* A congress of mathematicians
* A faculty of mathematicians
You could also get creative and use a noun that reflects their work:
* A theorem of mathematicians
* A formula of mathematicians
* A proof of mathematicians
* A puzzle of mathematicians
Ultimately, the best choice depends on the specific context and the desired tone.