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    • CommentRowNumber1.
    • CommentAuthorIan_Durham
    • CommentTimeJun 21st 2010

    Created a stub for no-go theorem. I’d like to organize it so that Bell’s theorem, the Kochen-Specker theorem, and Gleason’s theorem are referenced from the no-go theorem entry in the QM contents. Any objections?

    • CommentRowNumber2.
    • CommentAuthorTim_van_Beek
    • CommentTimeJun 22nd 2010

    No objection in principle, but maybe we need a sharper distinction of results that are not intuitive and those who directly contradict claims made in most textbooks, examples of the opposite ends of the spectrum would be (from my viewpoint) Gleason’s theorem, which is more of a Go-theorem for the algebraic approach to quantum logic, and Haag’s theorem wich says that the interaction picture used in most QFT textbooks does not exist (at least not in the sense claimed).

    • CommentRowNumber3.
    • CommentAuthorUrs
    • CommentTimeJun 22nd 2010
    • (edited Jun 22nd 2010)

    I am a bit sceptical. The term “no-go theorem” says more about the culture that the theorem was found in than the nature of the theorem itself.

    And if we have an entry on it, how meaningful is it to say that no-go theorems have their place in theoretical physics? The evident interpretation of the term clearly has no restriction to physics.

    The point is rather that theoretical physicists developed the habit of calling some theorems “no-go theorems”. I think it s more a reflection of the operational way of thinking in physics. They call it a no-go-theorem if it prevents proceeding along the naive track, in the same vein as they call it an “anomaly” if things don’t proceed as naively as normal. It is part of the general attitude of first proceeding and then solving the problems as they become apparent.

    I would opt for making it clear in the entry that “no-go theorem” is more than a technical term a piece of physics jargon.

    • CommentRowNumber4.
    • CommentAuthorIan_Durham
    • CommentTimeJun 23rd 2010

    Sorry for the delay in responding. I’ve been caught up in some work.

    I have no objection to any of the above points.

    Question: is there a way to more correctly/succinctly categorize (for lack of a better term) the theorems I mentioned in that entry?

    • CommentRowNumber5.
    • CommentAuthorzskoda
    • CommentTimeJun 24th 2010

    Word no-go theorem is used in mathematics as well. It is however the matter for English Dictionary. Any attempt at list would give thousands of negative existence theorems.

    • CommentRowNumber6.
    • CommentAuthorIan_Durham
    • CommentTimeJun 24th 2010
    Any suggestions, then, on making this more clear? Those three theorems are very much related and they are all no-go theorems in the physics sense, but clearly there's a broader meaning to the term (it is used fairly specifically in quantum information and quantum foundations).
    • CommentRowNumber7.
    • CommentAuthorUrs
    • CommentTimeMay 12th 2019
    • (edited May 12th 2019)
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