* Cosmic: This is a more general term that refers to the universe as a whole.
* Astrophysical: This focuses on the physical properties and processes of celestial objects.
* Cosmophysical: This term combines the aspects of cosmology and physics.
* Universe-related: This is a more straightforward and less formal option.
* Universal: This term emphasizes the scope of the subject.
The best substitute will depend on the specific context of your writing.