Fields based on whether someone is connected or not

Hi ! Thanks for the excellent plugin ??

I would like to know if it is possible to have fields that appear or not depending on whether someone is connected or if he isn’t.
For instance it could be useful to present an email field for someone not connected but useless (or even negative) for someone registered and connected.

One extra question : when we hide automatic fields, how to add an author fields so not connected users can upload a post with their pseudo ?

Thanks for your help and congrats again for the excellent plugin.