"apply the theory to" is correct and usable in written English.
You can use it when you want to refer to the practical application of a particular concept, principle, model, or theory. For example: "We need to apply the theory of natural selection to better understand how plants and animals in this region have adapted to their environment."
Attempts were made to apply the theory to more complicated systems than the hydrogen atom.
But when you try to apply the theory to humans, you hit a snag.
That is our biggest challenge, on how to help them apply the theory to application".
Assuming you can take this idea at face value, it should be possible to apply the theory to The Unconsoled.
Someone has to be wrong.Trying to apply the theory to this year's batch of wild weather causes even more headaches.
But the reality is that whether or not the right behavior emerges actually depends on how a given simulation is set up; there is nothing like a general theory of how to apply the theory to real-world data, nor a general means by which to make sure that the system's goals actually accord with those of a programmer.
He has also recently been at work applying the theory to politics.
Historically, the most famous supposition about the moral effect of art on its audience is Aristotle's theory of catharsis; Aristotle applied the theory to tragedy only, but many since his day have applied it to art in general.
Several philosophers have applied the theory to aesthetics, ethics, and philosophy of the social sciences.
Ill-conditioning was previously reported as an impediment to applying the theory to problems of practical importance.
Bullard and Sebald (1977) applied the theory to update the inverse matrix in SAM (social accounting matrix) analysis and developed an algorithm yielding the correspondence among the elements.
