Orthogonal Universe

The Orthogonal Universe gets its name from the trilogy set in it.

It's a universe with a subtly altered physics of spacetime (with wide-reaching consequences). It's extensively documented on Greg Egan's homepage.

Recurring elements
The physical basis of the universe itself is unique. The very plotlines of the stories set in this universe rank specifically around it - it's quite hard to miss.

Works

 * Orthogonal: The Clockwork Rocket
 * Orthogonal: The Eternal Flame
 * Orthogonal: The Arrows of Time