This is something that I've had many heated debates about, but I think I proved that Author Rank is a factor, and this is how I did it...and it was a mistake by the way. But you could try it too.
(Unfortunately, because my client data is confidential, I can't share too many intimate details.)
I had a client who has a responsive WP theme. However, they have so much content, the responsive theme just isn't the best solution-- not as good as a mobile site-- for this particular client.
I put up a mobile site at mobile.example.com and I set up the canonical link to point to the main domain, just as it should. The mobile site was also a WP site.
However, when I made the mobile site, I accidentally left myself as the author. (I built the mobile site before I added the site owner as a user.)
A couple of weeks later, MY FACE started appearing in the Google results instead of the attorney. In other words, the attorney used to rank on page 2 for "What are the consequences of DUI in Arizona?"
And it was at something like: example.com/consequences-dui-az-something
But suddenly mobile.example.com/consequences-dui-az-something appeared on page one of Google, with my face. The rankings changed and Google preferred to believe that I was the author, rather than the attorney with his brand new authorship.
So even though I added duplicate content and a canonical tag, Google preferred the content that was authored by me, and chose to display that over the identical content that the attorney wrote and had been previously indexed and given author credit for. All of a sudden, the mobile site took precedence. When I changed authorship back to the attorney, rankings dropped slightly again and Google chose to display the MAIN site (as it should have), rather than the mobile.
I don't care what anyone (even Matt Cutts) says about Authorship. I've seen a real life example. Perhaps they are using it in certain markets and not others. But when it comes to attorneys, my primary client, I've seen it matter.