During my application, i have mentioned the name of the professors with whom i want to work for my phd. I have emailed them before applying although none of them replied, However, i have to mention their name as it was mentioned in the application to write the name of POI in the sop. Now, it's been 3 month since i applied. But got no reply still. I think the professors whose name i have mentioned have already made offers to other students. Now can I contact any other professor in the department whose name i haven't mentioned in the sop?