The title of the book is not the real name, the author always uses the title of the book.
It may be, it may not be. The title of the book is the name of a book written by the author.
The real name is a legal title for everyone after birth.
Under normal circumstances, the two have nothing to do with each other. If an author suddenly gets the idea to write a book, it's not impossible for the title to be the author's real name, but I haven't seen it so far.