Reg : OAuth based authentication API rate Limit



I had look at API rate limit in twitter developer section. I just wanted to know is there any API rate limit for OAuth based twitter authentication. Here we are fetching the user details like id,name…etc.

Suppose more than 1000 people are accessing at same time to authenticate the twitter account . Is there any rate limit for the same.

I’m doing below API calls

Please can some one suggest, how many user authenticate at the same time . Is there any API rate limit for daily bases .