Sean Gullette
Sean Gullete wrote the screenplay for Pi which he stars in and is directed by Darren Aronofsky who he's been a longtime collaborator with. Sean has appeared in such films as Happy Accidents and Requiem for a Dream, also directed by Aronofsky. Gullette also wrote the screenplay for his feature debut as a director entitled Traitors. He is married to Yto Barrada whom he has two children with.
Mark Margolis
Mark Margolis studied with Stella Adler and at The Actors Studio in New York City. He's collaborated with Darren Aronofsky multiple times including the films Requiem for a Dream, The Fountain, The Wrestler, Black Swan and Noah. He is also a stage actor and currently appearing on the AMC series Better Call Saul.
Ben Shenkman
Ben Shenkman is best known for his role on the USA series Royal Pains. He received his MFA from NYU's Tisch School of the Arts. After playing the role of Louis Ironson in Angels in America on stage he reprised his role for the HBO Mini-Series adaptation of Tony Kushner's award-winning play. He appeared in another Aronofsky film, Requiem for a Dream two years after Pi.