Quantum Field Theory

In modern theoretical physics, quantum field theory is the framework for constructing quantum mechanical models of subatomic particles in particle physics. Here are all the Insights that have been tagged as relevant to Quantum Field Theory.

In ordinary quantum mechanics (QM), you treat particles quantum mechanically.

In quantum field theory (QFT), you treat fields quantum mechanically. It turns out that in addition to the classically known fields (like the electromagnetic field) there are new “quantum fields” for all fundamental particles (like the electron). In this sense, QFT is more fundamental than ordinary QM. The most fundamental theory up to date -the Standard Model of particle physics- is a QFT.

Articles for: Quantum Field Theory

Kuhnian Revolution

Modern Physics Understood as an Unrecognized Kuhnian Revolution

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People often claim on Physics Forums and in the foundations community proper that quantum mechanics is "incomplete." Indeed, Lee Smolin recently wrote…
qft_renormalization

Learn Renormalization in Mathematical Quantum Field Theory

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This is one chapter in a series on Mathematical Quantum Field TheoryThe previous chapter is: 15. Interacting quantum fields. 16. Renormalization In…

Learn Interacting Quantum Fields in Mathematical Quantum Field Theory

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This is one chapter in a series on Mathematical Quantum Field Theory.The previous chapter is 14. Free quantum fields.The next chapter is 16. Renormalization. 15.…
qft_freequantum

Learn Free Quantum Fields in Mathematical Quantum Field Theory

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This is one chapter in a series on Mathematical Quantum Field TheoryThe previous chapter is 13. Quantization.The next chapter is 15. Interacting…
qtf_quantization

Learn Quantization in Mathematical Quantum Field Theory

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The following is one chapter in a series on Mathematical Quantum Field Theory.The previous chapter is 12. Gauge fixing.The next chapter is 14.…
qft_gauge

Learn Gauge Fixing in Mathematical Quantum Field Theory

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The following is one chapter in a series of Mathematical Quantum Field Theory.The previous chapter is 11. Reduced phase space.The next chapter…
qtf_phased_space

Learn Reduced Phase Space in Mathematical Quantum Field Theory

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The following is one chapter in a series on Mathematical Quantum Field Theory.The previous chapter is 10. Gauge symmetries.The next chapter is…
arnold

Interview with Mathematician and Physicist Arnold Neumaier

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Please give us a brief background on yourself Over 40 years ago, I studied mathematics, physics and computer science in Freiburg and Berlin (Germany).…
qtf_guagesym

Learn Gauge Symmetries in Mathematical Quantum Field Theory

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This is one chapter in a series on Mathematical Quantum Field Theory.The previous chapter is 9. Propagators.The next chapter is 11. Reduced phase…
qft_prapagators

Learn Propagators in Mathematical Quantum Field Theory

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This is one chapter in a series on Mathematical Quantum Field Theory.The previous chapter is 8. Phase space.The next chapter is 10. Gauge symmetries. 9.…
qtf_phasespace

Learn Phase Space in Mathematical Quantum Field Theory

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The following is one chapter of a series on Mathematical Quantum Field Theory.The previous chapter is 7. Observables.The next chapter is 9. Propagators. 8.…
qtf_observables

Learn Observables in Mathematical Quantum Field Theory

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The following is one chapter in a series on Mathematical Quantum Field Theory.The previous chapter is 6. Symmetries.The next chapter is 8. Phase…
qtf_symmerities

Learn Symmetries in Mathematical Quantum Field Theory

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The following is one chapter in a series on Mathematical Quantum Field Theory.The previous chapter is 5. Lagrangians.The next chapter is 7. Observables.  6.…
qft_lang

Learn Lagrangians in Mathematical Quantum Field Theory

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This is one chapter in a series on Mathematical Quantum Field Theory.The previous chapter is 4. Field Variations.The next chapter is 6. Symmetries.  5.…
qtf_field_variations2

Learn Field Variations in Mathematical Quantum Field Theory

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This is chapter 4 of a series on Mathematical Quantum Field Theory.The previous chapter is 3. Fields.The next chapter is 5. Lagrangians.  4.…
qtf_fields

Learn the Fields of Mathematical Quantum Field Theory

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The following is one chapter in a series on Mathematical Quantum Field TheoryThe previous chapter is 2. Spacetime.The next chapter is 4. Field…
qft_spacetime

Learn Spacetime in Mathematical Quantum Field Theory

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The following is one chapter in a series on Mathematical Quantum Field Theory.The previous chapter is 1. Geometry.The next chapter is 3. Fields  2.…
qtf_geometry

Learn the Geometry of Mathematical Quantum Field Theory

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This is the first chapter in a series on Mathematical Quantum Field Theory.The next chapter is 2. Spacetime. 1. Geometry The geometry of physics…
quantumfieldtheory

A First Idea of Quantum Field Theory – 20 Part Series

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These notes mean to give an expository but rigorous introduction to the basic concepts of relativistic perturbative quantum field theories, specifically…
perturbation

Introduction to Perturbative Quantum Field Theory

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This is the beginning of a series that gives an introduction to perturbative quantum field theory (pQFT) on Lorentzian spacetime backgrounds in its…
entanglement_entropy2

Lesson on Entanglement Entropy in Quantum Field Theory

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Part 1: Quantum Mechanics[This article expects the reader to have some experience with quantum field theory and path integrals][I should also…
quantumflux

Learn About Vacuum Fluctuations in Experimental Practice

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This Insight Article is a sequel of the Insight Articles ”The Physics of Virtual Particles”, “Misconceptions about Virtual Particles“ , and ''The…
quantumapplitudes

Learn About Quantum Amplitudes, Probabilities and EPR

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This is a little note about quantum amplitudes. Even though quantum probabilities seem very mysterious, with weird interference effects and seemingly nonlocal…
spacetimecon

Struggles with the Continuum: Spacetime Conclusion

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 We've been looking at how the continuum nature of spacetime poses problems for our favorite theories of physics --- problems with infinities.…
spacetime7

Struggles with the Continuum: General Relativity

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 Combining electromagnetism with relativity and quantum mechanics led to QED. Last time we saw the immense struggles with the continuum this…
virtualparticlesmyths

Learn the Top Misconceptions about Virtual Particles

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This Insight Article is a sequel to the Insight Article ''The Physics of Virtual Particles'', which contains an exposition of definitions that are physically…
virtualparticles

Learn the Physics of Virtual Particles in Quantum Mechanics

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In discussions on the internet (including a number of Wikipedia pages) and in books and articles for non-experts in particle physics, there is considerable…
spacetime5

Struggles with the Continuum: Quantum Electrodynamics

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  Quantum field theory is the best method we have for describing particles and forces in a way that takes both quantum mechanics…
spacetime4

Struggles with the Continuum – Relativity and Quantum

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 In this series, we're looking at mathematical problems that arise in physics due to treating spacetime as a continuum---basically, problems…
perbation theory

Introduction to Causal Perturbation Theory

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Relativistic quantum field theory is notorious for the occurrence of divergent expressions that must be renormalized by recipes that on first sight sound…
renormalization

Quantum Renormalisation Made Easy

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What Is The Issue With Renormalisation If you have an interest in physics you have likely come across renormalisation before, although what it really…