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1. How to count and 'see' the symmetry factor of Feynman diagrams?
Link: https://physics.stackexchange.com/questions/150085/how-to-count-and-see-the-symmetry-factor-of-feynman-diagrams
Description: WEBThe procedure is quite simple: the symmetry factor counts how many of the same diagrams you would be counting if you didn't consider that the single particles in your diagrams are identical. To do this, ask yourself "how many of this same diagram can I make?" where "same diagram" means "same external particles, same connections, and …
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2. Feynman diagram - Wikipedia
Link: https://en.wikipedia.org/wiki/Feynman_diagram
Description: WEBThe symmetry factor theorem gives the symmetry factor for a general diagram: the contribution of each Feynman diagram must be divided by the order of its group of automorphisms, the number of symmetries that it has.
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3. Theoretical Plate Number and Symmetry Factor - SHIMADZU …
Link: https://www.shimadzu.com/an/service-support/technical-support/analysis-basics/basic/theoretical_plate.html
Description: WEBSymmetry factor (S, also called "tailing factor") is a coefficient that shows the degree of peak symmetry. It is represented in equation (5) based on the measurements shown in Fig. 2. S>1: Tailing peak. S=1: Peak with Gaussian distribution (symmetry) S<1: Leading peak.
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4. How to count symmetry factors of Feynman diagrams?
Link: https://mathoverflow.net/questions/26897/how-to-count-symmetry-factors-of-feynman-diagrams
Description: WEBThe symmetry factor is precisely the number of automorphisms of the graph, defined as follows: Definition: A Feynman graph is a collection $H$ of half edges along with two partitions: one ( edges ) into sets of size precisely $2$, and the other ( vertices ) into sets of size at least $3$.
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5. Definition and proof of Symmetry Factor of Feynman Diagram
Link: https://physics.stackexchange.com/questions/694157/definition-and-proof-of-symmetry-factor-of-feynman-diagram
Description: WEBFeb 12, 2022 · Studying QFT, I was told that symmetry factor is defined by: if there are m m ways of arranging vertices and propagators to give identical parts of a diagram (keeping the outer ends of external lines fixed and without cutting propagator lines) we get a factor Di = m D i = m. The symmetry factor is given by the product of all symmetry factors D ...
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6. A General Expression for Symmetry Factors of Feynman …
Link: https://arxiv.org/pdf/hep-th/0108088.pdf
Description: WEB(February 1, 2008) Abstract. The calculation of the symmetry factor corresponding to a given Feynman diagram is well known to be a tedious problem. We have derived a simple formula for these symmetry factors. Our formula works for any diagram in scalar theory (φ3 and φ4 interactions), spinor QED, scalar QED, or QCD.
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7. Formula for calculating symmetry factors for Feynman diagrams?
Link: https://math.stackexchange.com/questions/4308385/formula-for-calculating-symmetry-factors-for-feynman-diagrams
Description: WEBNov 17, 2021 · The symmetry factor for a diagram with adjacency matrix A A (including both internal and external vertices) is. S =|Aut(A)| ∏i=1V+T ∏j=iV+T Aij!, S = | Aut. ( A) | ∏ i = 1 V + T ∏ j = i V + T A i j!, where Aut(A) Aut. ( A) is the graph automorphism group of the graph with adjacency matrix A A, and.
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8. Symmetry Factors of Feynman Diagrams for Scalar Fields
Link: https://arxiv.org/pdf/0907.0859.pdf
Description: WEBWhat is the symmetry factor? How is it constructed? We consider a pth-order expansion of the n-point correlation function in a real scalar theory with the interaction Lint = (λ/4!)φ4: (1/p!)(1/4!)ph0|T [φ(x1)φ(x2)...φ(xn)φ4(y1)φ4(y2)...φ4(yp)]|0i, (1)
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9. Symmetry factor of Feynman diagram in - Physics Stack Exchange
Link: https://physics.stackexchange.com/questions/606583/symmetry-factor-of-feynman-diagram-in-phi4-theory-at-second-order
Description: WEBJan 10, 2021 · The correct answer is S = 4 S = 4 (in that the Feynman diagram gets a multiplicative factor of 1 4 1 4) but I get S = 8 S = 8 with the following reasoning. For each closed loop, we can exchange the lines that start/end in the loop and belong to it. So, each loop gives a factor of 2 2.
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10. Symmetry Factors of Feynman Diagrams for Scalar Fields
Link: https://arxiv.org/abs/0907.0859
Description: WEBJul 5, 2009 · The symmetry factor can be separated into two ones corresponding to that of connected and vacuum diagrams. The determination of symmetry factors for the vacuum diagrams is necessary as they play a role in the effective …
