Another in a series of Gorgonzola's nitpicking nodes.

Although it is reasonable to assume that Louis Wu's biological father is Carlos Wu, and that he was raised by his mother Sharrol Janss and Beowulf Shaeffer, author Larry Niven never explicitly states this.

We learn in the story "Grendel" (appearing in Niven's collection Neutron Star), as well as the story "The Borderland of Sol" (appearing in Tales of Known Space), that although Shaeffer and Janss wanted to have children, Earth's population control laws forbade1 Beowulf Shaeffer from having children on Earth. This wouldn't have been a problem if Sharrol hadn't been psychologically unable to leave Earth.

Fortunately (or at least conveniently) those same laws granted unlimited reproduction licenses to certain individuals, one of whom was Carlos Wu, a friend of Shaeffer and Janss.

In "The Borderland of Sol", the only story containing Beowulf Shaeffer and Carlos Wu as characters, we learn that the children's names are Louis and Tanya.

Unfortunately, Louis Wu never treats us to reminiscences about his daddy Beowulf Shaeffer. What's more, in Ringworld, Wu and his Kzinti companion Speaker-to-Animals ride a special second-generation hyperdrive to the homeworld of the Pierson's Puppeteers, referring obliquely to the human who had tested it, never mentioning his name: Beowulf Shaeffer2.

When I read all of these stories many years ago, these misconnections kept me awake more than once, wondering what was going on.
1Because Shaeffer was an albino, the same reason his ancestors were forbidden to produce children on Earth, and why they emigrated to Shaeffer's homeworld, We Made It.
2"At the Core", also in Tales of Known Space.