Is there a url to the author's page for a particular tumblr blog?
In the tumblr docs the author url just links to the author's own tumblr blog.
Ie, Is it possible to filter posts of a blog to a particular author?
I'm fairly sure the only filtering you can do on posts (at least in the basic format, I know nothing of the API) is using tags. If the posts aren't tagged for author, then you probably can't. As noted here:
Tumblr has only two main types of page:PermalinkPage IndexPageIndexPage include 3 sub-types:TagPage DayPage SearchPage
If what you want to filter for can't be achieved by these (and I'm fairly sure filtering using