I bought a domain name for my blog blogger, it was its pagerank 2, now with the new domain name it went to 0 what can i do ? http://www.ubun2.info/
Zero, nothing, nada, zippo - unless any of us/you work for Google. Ask google but don't ask it here. And no offence but I doubt most peoples first search in the morning is for "ubun" - BBC world news, maybe but not "ubun"
That's a great domain name! I search for "ubuntu this" and "ubuntu that" all the time. As for your PR, you will have to wait... and wait... and wait... When it comes back it will come back as PageRank 2 or higher, assuming you put in 301 or 310 redirects from your old blog to your new domain name.
when you changed the domain name, you lost any backlinks you had. When you get backlinks for the new domain name , your PR will go up again. But really PR is just a number - it's a diagnostic of how Google sees your backlinks, it means nothing in itself (and PR2 is pretty poor - 3 is pretty much the default)
The PR is belong to the page itself, if you change the domain, sure the PR is different because they are different page
Make all the outgoing links "no-follow".It will help crawler to long last on your website and hence help to increase page rank