There isn't a specific term for a collection of matter that does not interact with anything else in the universe. This is because such a scenario is hypothetical and violates fundamental laws of physics.

Here's why:

* Gravity: All matter with mass exerts gravitational force, meaning it interacts with other matter. Even if a collection of matter were isolated from other objects, it would still be affected by the gravity of distant galaxies and other cosmic structures.

* Quantum Mechanics: Even at the smallest scales, particles interact via fundamental forces like the strong and weak nuclear forces and the electromagnetic force. This means complete isolation is impossible.

In summary:

* The idea of a collection of matter completely isolated from the rest of the universe is a theoretical concept.

* It's not something we've observed or can realistically achieve due to the fundamental laws of physics.

Therefore, there isn't a specific term for this because it's not a real-world phenomenon.