In the TV series "The Expanse," the Ring travelers do not experience time dilation because the Ring network operates outside the influence of normal spacetime. The Rings are an advanced alien technology known as the "Ring gates" that connect different star systems across the galaxy.
The Ring gates create stable wormholes, allowing near-instantaneous travel between different star systems. When a spacecraft passes through a Ring gate, it enters a subspace realm called the "slow zone" or "hub space," where time functions differently.
Inside the slow zone, time does not flow at the same rate as in normal spacetime. It is a realm where the laws of physics are altered, and time dilation effects are nullified. This means that no matter how far a spaceship travels through the Ring network or at what speed, there will be no noticeable time dilation relative to the point of departure.
This unique property of the Ring gates enables characters in "The Expanse" to travel vast distances across the galaxy without experiencing the time dilation effects that would otherwise occur according to the principles of general relativity.
It's important to note that the depiction of the Ring gates and their properties in "The Expanse" is a fictional concept created for the purpose of the story and does not reflect our current understanding of physics or real-world possibilities for interstellar travel.