physics, mathematical physics, philosophy of physics
theory (physics), model (physics)
experiment, measurement, computable physics
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Types of quantum field thories
In physics given two physical system their composite is meant to be both systems regarded as a single system, but trivially so, without the two interacting.
In classical mechanics forming a composite in this sense amounts to taking the cartesian product of their phase spaces.
In quantum mechanics forming the composite amounts to taking the (non-cartesian) tensor product of the spaces of quantum states.
twisted generalized cohomology theory is conjecturally ∞-categorical semantics of linear homotopy type theory: