Display Author Main Blog Page

On the main blog page, the post date is displayed above the post title, but not the author. On the post page, both are displayed above the title. Is there a way to display the author (byline) on the main blog page? On the post I see the reference is class byline, and the css is
.single .byline, .group-blog .byline {
display: inline;
}

Is there any css that will display it on the main blog page, or is does that require modification of a theme file?

Thanks for any help you can give!