Two-dimensional gas

A two-dimensional gas is a collection of objects constrained to move in a planar or other two-dimensional space in a gaseous state. The objects can be: classical ideal gas elements such as rigid disks undergoing elastic collisions; elementary particles, or any ensemble of individual objects in physics which obeys laws of motion without binding interactions. The concept of a two-dimensional gas is used either because: the issue being studied actually takes place in two dimensions ; or, the two-dimensional form of the problem is more tractable than the analogous mathematically more complex three-dimensional problem.

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