Fox’s Empire debuted to big ratings last week — and its second episode was even bigger. Per preliminary Nielsen data, Wednesday’s second episode of the hip-hop Dynasty scored a 4.0 rating among viewers under 50 and drew 10.3 million viewers, up from last week’s 3.8 rating and 9.9 million viewers. This sort of week-two bump almost never happens these days among broadcast shows; networks almost always expect at least a 10 percent decline. The fact that Empire went up indicates that viewers who watched the premiere last week liked what they saw and told some friends. It also pretty much guarantees the show will be renewed for a second season, with an announcement of a pickup possible as soon as this weekend’s Fox session at the TCA press tour.