Google+ will allow you to use pen names or professional names if that s what you go by in daily life. With millions of users, a credible pseudonym or online handle (no dead presidents, people!) coupled with a valid e-mail (or, better yet, gmail) account and some other verifiable online assets will likely fool Google’s identity police. Google has also taken a hard stand on groups, like the hacking collective Anonymous, that hoped to use Google+ to reach people.
Source: https://threatpost.com/calling-mark-twain-pseudonyms-on-g/91847/