What is the fine-grained topic of the following text: Among five freestyle skiing events in the Winter Olympics – moguls, aerials, ski halfpipe, ski cross, and ski slopestyle – Caldwell competes in ladies' aerials, in which she skis off a 2- to 4-meter jump and attempts tricks such as flips and twists. Only return the topic.
Caldwell competing in Ladies' Aerials in Freestyle Skiing at the Winter Olympics