Time Travel Inhibitors

Much like transport inhibitors, frozen space-time in the past can be entangled, after the fashion of replicators, and anchored to prevent disruption, thereby preventing time travel.

This is an overly simplistic, but essentially illustrative way to envision the field effect of temproal change inhibitors acting upon the effectively (but higher dimensionally) 3-dimensional relationship between timelines.

Imagine a tree with 1 trunk, but many branches emanating from it.