After the great success of “The Fighter”, Hollywood returns to the city of Lowell this week to film “Here Comes the Boom”, an action-comedy starring Kevin James, Salma Hayek and Henry Winkler. The film is about a high school science teacher who becomes involved in mixed martial arts in an effort to raise money to save the school’s music program. Hundreds of extras are needed each day this week at the Tsongas Center (formerly known as the Tsongas Arena) for the filming of the fight scenes. For more information about the film and about becoming an extra, check this out.