"detailed theory" is a correct and usable phrase in written English.
You can use it when you want to refer to a set of ideas or concepts that go into depth and offer a thorough explanation. For example, "The book contained an in-depth detailed theory on the factors that affect economic growth."
"DfID has not yet developed a detailed theory of change outlining how its proposed investments and those of new alliance partners will reduce undernutrition," the report said.
Previous work in controlling the behavior of brain slices was based more closely on the detailed theory of chaos, Dr. Gluckman said.
3) He doesn't advance a detailed theory of what "really" happened in the immediate aftermath of Good Friday and Easter Sunday, choosing agnosticism instead.
Although the sutras do not explicitly develop a detailed theory of causation, the later Nyaya theory is sufficiently delineated in Chapter 4. No event is uncaused.
Davis (2003) develops a detailed theory of meaning that combines (P) with a version of the use theory of meaning.
It is not until late in book I that he begins to develop his own detailed theory of their distinctive contributions to generation.
Detailed theory-experiment comparisons show that the anisotropic forbidden transition can be mainly attributed to indium (In) segregation effect.
All characters should be able to quote Lou Reed at length, and have intensely detailed theories about their favourite popstar.
He detailed a theory to explain the anomalous movements of the moon, which appears to change speed during its orbit of the Earth.
In this paper, Einstein detailed his theory of special relativity, which enabled scientists to better understand movement at the speed of light.
The detail theory of the method is already explained in the previous sections.
