Is it possible to know that?,like when were they deleted, by which user, etc; or is any information regarding the files completely erased
If by delete, you mean "moved to the trash bin", yes and no. You'll always know who moved the file to the trash, because it'll end up in their trash bin. You won't know when it was moved to the trash, because move operations don't update the file's timestamp.
If by delete, you mean
Of course, if you perform regular backups, you can extrapolate a time window for the deletion.
If you are interested a particular file or directory
Note that without inotify's
This is probably not even close to what you are looking for, but it may be of use. The comparison to backups suggested by djeikyb will give you far more detailed information.