nLab no-go theorem

Idea

A no-go theorem is generally understood to be any theorem, usually in theoretical physics, that shows that an idea is not possible even though it may appear as if it should be. Many no-go theorems include hidden, implicit assumptions.

Examples of no-go theorems in theoretical physics include

in foundations of quantum physics:

• Bell's theorem,

• Kochen-Specker theorem

• Gleason's theorem.

in quantum field theory:

• Coleman-Mandula theorem

in supergravity:

• no de Sitter spacetime (?)

• no ekpyrotic cosmology (?)