Summertime reruns of CBS's The Big Bang Theory on Monday night appear to be turning the comedy into a bona fide hit. Paired with the CBS hit Two and a Half Men on Mondays, the show's ratings have been rising steadily -- up more than 50 percent from last summer. And this week, it pulled ahead of Two and a Half Men among viewers 18-49 and came close to doing so among total viewers as well. Men captured 8.3 million viewers; Theory , 8.1 million.