I have applied to a professor from another university - and from another country, in case that is relevant - about doing my undergraduate thesis under him.
He said he liked my profile and asked me for some documents (transcripts, recommendation letters, etc). After I sent him these documents, he stopped responding.
Before this I used to keep him updated about the process (when I will get my transcripts, when my recommenders will send him the letters, etc) and during this time he would always acknowledge the receipt of my mails. After my recommenders sent him their letters, he stopped responding. I know how this might look, but I have no reason to suspect that my recommenders might have anything bad to say about me. I have used their recommendations to get a scholarship previously.
This hiatus in communication took place in December last year, so this might very well be because he was on leave during this period. I verified that his university began its semester last week and mailed him, again to no response.
How do I interpret his silence? There is of course no certain answer to this. So the more important question is, should I keep politely following up - say, dropping him a mail every week or so asking if he's made a decision yet?
Note: This question on Academia.SE has a comment which says that "treat a non-response as the (reasonably expected) negative response" about emailing a professor at a foreign university. However, I don't think that applies in my case as the professor had initially expressed his interest in hiring me, so I thought he would let me know if he had later changed his mind.