How much is an average time of waiting to receive a reply from Professional co-author? I have sent my manuscript to a professor of math about one month ago. This manuscript was written according to his encouragement for a joint research work. He told me that send him what I have done from my side, and then he will add additional materials from his own side. I want to send a tracking email about the status of that. Should I do that or I must wait for his reply?
&quot;I want to send an email email asking him for an update about the
status of that. Should I do that or I must wait for his reply?&quot;

Absolutely. Why? Because it has been 1 month and you have not received any communication from him yet. Usually after waiting a full 7 days, it is not inappropriate to send a follow-up email.

&quot;How much is an average time of waiting to recieve a reply from
Professional co-author?&quot;

It varies. Some people reply the same day, some the same hour, but it's also not uncommon for people to take a month or two to reply.
Usually it is not inappropriate to ask for an update 7 days after the first email. Another one after another 7 days can also often be considered okay. It's when you send more than 2 follow-up emails, or when you do not wait ~7 days between them, that it might start to be seen as &quot;nagging&quot;, but even then that's not always the case. Please send him a follow-up email and ask us what to do if you still have problems after that. My guess is that he'll reply (since he asked you for the manuscript).