scientific theory
Refers to a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment.
The theory of evolution is an important scientific theory.
That scientific theory has been verified by many experiments.
仮説 is a hypothesis, a proposed explanation made on the basis of limited evidence as a starting point for further investigation, while 科学理論 is a well-established explanation supported by extensive evidence.
法則 is a scientific law, a statement based on repeated experimental observations that describes some aspect of the universe, often expressed mathematically, while 科学理論 is a broader explanatory framework.
Compound of 科学 (science) and 理論 (theory).