David Callan Sydney. David Callan David Callan is an actor and standup comedian based in Sydney, Australia. He is a former employee of ASIO; his comedy material is partly based on his experiences as a spy. In the 2011 sitcom "At Home with Julia", he played the recurring role of Agent Smith, one of the Australian Federal Police agents on the Prime Minister's security detail. In 2012, he appeared in two episodes of the TV series "Rake". He is sometimes confused with Dave Callan, another Australian standup comedian with an almost identical name. Callan has a wife and two children and lives
Curtis Callan students include Philip Argyres, Vijay Balasubramanian, William E. Caswell, Peter Woit, Igor Klebanov, Juan Maldacena, Larus Thorlacius, Alberto Güijosa and Justin B. Kinney. Callan is best known for his work on broken scale invariance (Callan–Symanzik equation) and has also made leading contributions to quantum field theory and string theory in the areas of dyon-fermion dynamics, string solitons and black holes. Callan has been a member of the JASON defense advisory group since 1968, and was chair of the group from 1990 to 1995. He served as president of the American Physical Society in 2010. Curtis Callan Curtis Gove Callan Jr.