Louis Wu is the son of Beowulf Shaeffer and Sharrol Janss. His biological father is Carlos Wu. He was born in 2650, and has an older sister named Tanya.
Louis Wu appears in the following stories by Larry Niven:

1. There is a Tide, 1968

2. Ringworld, 1970

3. The Ringworld Engineers, 1980

4. The Ringworld Throne, 1996

There is a Tide appears in the collection Tales of known space (1975).