How can I implement the possibility of having more than one author per blog post in mezzanine?
No idea, maybe you should ask on the Mezanine mailing list?
Thanks Fitora. Thats exactly what I did and this is what I got at post : https://groups.google.com/forum/#!topic/mezzanine-users/xhRJ_73po5k
"If you just want to display more authors you might be able to add an M2M to BlogPosts using field injection called something like additional_authors.
Making it so that additional authors could edit BlogPosts in the admin would be more complicated but probably doable. At worst you would have to unregister the BlogAdmin and then re register it with a custom blog admin that also allows additional authors to view/edit.
You can check out the OwnableAdmin which the BlogAdmin makes use of here:
To enter a block of code: