Learn English – “Any correction” or “any corrections”: Are they interchangeble

Both are possible. Said that, it depends on the context.

Collective nouns are tricky in that way. The example of 'team' is good one to ponder upon.

Say, you are considering the team as one entity. You then use a singular verb 'is'.

The team is at the top of ....

But then, if you want to treat each team member separately but still want to use the collective noun, it takes 'are'. Say -

The team are arguing among themselves.

Similarly, India have won the match is also correct.

It seems to me that the adequate title here is either "Parameters" or "Variables".

Usually, when you write a paper about some scientific work, your parameters/variables are not obvious. Naturally, you assign a name or a symbol to each one; but the main point of this section (if I understand correctly) is the variables, rather than the names.

Conversely, if the variables are commonly known and your naming system is an innovation, it makes more sense to title this part "Notation".