‘I had a chance to make something beautiful with this film,’ Oscar winner says. By Jocelyn Vena Natalie Portman in “Black Swan” Photo: FOX Searchlight A month after Natalie Portman took home the Oscar for her portrayal of a prima ballerina in Darren Aronofsky’s dark thriller “Black Swan,” controversy erupted regarding whether she had actually performed the dances in the film. Portman’s ballet body double, Sarah Lane , claimed that the majority of the dancing was performed by body doubles. Those who worked closely with the star in “Black Swan” promptly spoke out to defend Portman. Her fianc