他的研究聚焦于理论物理学。

His research focuses on ___theoretical physics.

Haken 教授是斯图加特大学理论物理研究所之一的著名负责人。

Prof. Haken is the renowned head of one of the institutes of ___theoretical physics at the University of Stuttgart.

在学术讨论中，理论科学与应用科学之间的区别至关重要。

The distinction between ___theoretical and applied science is crucial in academic discourse.