I am a postdoc in mathematics. I read a paper of a Chinese mathematician some time ago and I found out that I could extend it. Therefore, I dropped an email to him, and then he told me if I could do it, it would be an interesting result. He also told me " I would be happy to know if you have anything to share with me," I thought that meant he would like to work with me. So, I wrote an email to him that contains all of my ideas. Now, I found out that my ideas work and everything correct.
My problem is he hasn't replied to my email after two weeks and I might be pessimistic but I am scared he steals my ideas and whatever I explained to him.
Even though I am a postdoc, he is a well-known mathematician. Moreover, we both use university emails to contact each other. What should I do now? Thanks in advance.
I have been writing it, but what I can do if he published it before me