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In theoretical physics, a no-go theorem is a theorem that states that a particular situation is not physically possible. Specifically, the term describes results in quantum mechanics like Bell's theorem and the Kochen–Specker theorem that constrain the permissible types of hidden variable theories which try to explain the apparent randomness of quantum mechanics as a deterministic model featuring hidden states. ==Examples== The Weinberg–Witten theorem states that massless particles (either composite or elementary) with spin ''j'' > 1/2 cannot carry a Lorentz-covariant current, while massless particles with spin ''j'' > 1 cannot carry a Lorentz-covariant stress-energy. The theorem is usually interpreted to mean that the graviton (''j'' = 2) cannot be a composite particle in a relativistic quantum field theory. In quantum information theory, a no-communication theorem is a result that gives conditions under which instantaneous transfer of information between two observers is impossible. Other examples: * Coleman–Mandula theorem * Haag–Lopuszanski–Sohnius theorem * Antidynamo theorems (e.g. Cowling's theorem) * No-teleportation theorem * No-cloning theorem * No-broadcast theorem * Quantum no-deleting theorem 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「No-go theorem」の詳細全文を読む スポンサード リンク
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