The phrase "are theoretically rigorous" is correct and usable in written English.
It can be used when discussing concepts, theories, or methodologies that are based on sound theoretical principles and adhere to strict logical standards.
Example: "The proposed models are theoretically rigorous, ensuring that the results are both valid and reliable."
Alternatives: "are conceptually sound" or "are methodologically robust."
The aim is as much to encourage the development of empirical research that is theoretically rigorous and informed, as it is to encourage the empirical application of theoretical work (or at least to encourage theorists to explicitly signify how their work could be applied in an empirical manner).
Unfortunately, most yield curve models tend to be theoretically rigorous but empirically disappointing, or empirically successful but theoretically lacking.
The development process was theoretically rigorous, involved multiple stakeholders and the Diabetes Manual programme demonstrates strong face validity with both professionals and people with diabetes.
Spontaneous emission lifetime orientation distributions of a two-level quantum emitter in metallic nanorod structures are theoretically investigated by the rigorous electromagnetic Green function method.
Pierre-Louis explains that in the 1960s, Prof. Rainer Weiss was teaching a class on gravitational physics and "devised a method that he felt was theoretically more rigorous, using a clock and laser beams" to detect gravitational waves.
In this paper, the optical properties of the silicon square nanohole (SiSNH) arrays are theoretically studied via simulation based on the Rigorous Coupled Wave Analysis (RCWA) in detail.
Many are theoretically legal.
In this book, Francis Diebold and Glenn Rudebusch propose two extensions of the classic yield curve model of Nelson and Siegel that are both theoretically rigorous and empirically successful.
Furthermore, the stability of the closed-loop suspension system is theoretically guaranteed by rigorous mathematical analysis.
Among these methods, the stochastic-process-based method is theoretically the most rigorous but also computationally the most expensive.
Empirical reports must be theoretically and methodologically rigorous.
