In the modeling of physics, a toy model is a deliberately simplistic model with many details removed so that it can be used to explain a mechanism concisely. It is also useful in a description of the fuller model.
- In "toy" mathematical models, this is usually done by reducing or extending the number of dimensions or reducing the number of fields/variables or restricting them to a particular symmetric form.
- In "toy" physical descriptions, an analogous example of an everyday mechanism is often used for illustration.
Examples of toy models in physics include:
- the Ising model as a toy model for ferromagnetism, or lattice models more generally;
- orbital mechanics as described by assuming that Earth is attached to the Sun by an elastic band;
- Hawking radiation around a black hole described as conventional radiation from a fictitious membrane at radius r=2M (the black hole membrane paradigm);
- frame-dragging around a rotating star considered as the effect of space being a conventional viscous fluid.