Interpreting Feynman Diagrams as Visual Models

On the interpretation of Feynman diagrams, or, did the LHC experiments observe H → γγ?

“…However, this is a rather weak argument since even Feynman in 1948 did not intend to picture particle trajectories and Niels Bohr acknowledged already at the Pocono meeting that this remark was based on a misconception (Mehra, 1994, p. 248). In fact, the existence of particle trajectories is no compulsory precondition for a realistic reading of Feynman diagrams (compare also Wüthrich (2012)). The following quote by one of the leading QFT experts and Nobel laureate Frank Wilczek is instructive: "Feynman diagrams look to be pictures of processes that happen in space and time, and in a sense they are, but they should not be interpreted too literally.…”

The Exigencies of War and the Stink of a Theoretical Problem: Understanding the Genesis of Feynman’s Quantum Electrodynamics as Mechanistic Modelling at Different Levels

“…apparatus was supposed to describe (see also Wüthrich 2012). Presentday philosophy of science provides much literature on these terms and I am afraid I will gloss over many subtleties regarding the issues discussed there.…”

“…Feynman showed that this matrix is equal to the unit matrix α (see the lowest of the highlighted areas in Figure 3). I've reconstructed the details of Feynman's "struggle" with the Dirac equation in Chapter 4 of the Genesis of Feynman Diagrams (Wüthrich 2010). A discussion of some of the documents on which my reconstruction is based has also been discussed in the seminal work on the history of QED by Silvan S. Schweber (Schweber 1994(Schweber , especially p. 406-07, 1986a.…”

“…Finally, I will contrast my findings with similar studies, especially with Peter Galison's, in which Feynman's war-related work takes center stage (Galison 1998). To a considerable extent, I will build on my own reconstruction of the genesis of Feynman diagrams, which in turn is based on my selection of documents from the Feynman Papers hosted at the California Institute of Technology (Wüthrich 2010).…”

Solutions in Constructive Field Theory

“…There is also an open question of whether the diagrammatic methods used to manage expansions in constructive QFT have any physical content. 24 This is related to ongoing debates about whether Feynman diagrams in Lagangian QFT are merely a convenient calculational tool or have real physical content (Wüthrich, 2012). The lack of mathematical rigor of Lagrangian QFT may be a reason to dismiss the foundational importance of techniques associated with Lagrangian QFT, such as the RG and Feynman diagrams, but their continued importance even in rigorous enterprises like constructive QFT removes this reason.…”