### Posts

### 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…

### Learn Renormalization in Mathematical Quantum Field Theory

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

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.…

### Learn Free Quantum Fields in Mathematical Quantum Field Theory

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

### Learn Quantization in Mathematical Quantum Field Theory

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.…

### Learn Gauge Fixing in Mathematical Quantum Field Theory

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

### Learn Reduced Phase Space in Mathematical Quantum Field Theory

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

### Interview with Mathematician and Physicist Arnold Neumaier

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

### Learn Gauge Symmetries in Mathematical Quantum Field Theory

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…

### Learn Propagators in Mathematical Quantum Field Theory

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.…

### Learn Phase Space in Mathematical Quantum Field Theory

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.…

### Learn Observables in Mathematical Quantum Field Theory

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…

### Learn Symmetries in Mathematical Quantum Field Theory

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.…

### Learn Lagrangians in Mathematical Quantum Field Theory

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.…

### Learn Field Variations in Mathematical Quantum Field Theory

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.…

### Learn the Fields of Mathematical Quantum Field Theory

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

### Learn Spacetime in Mathematical Quantum Field Theory

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.…

### Learn the Geometry of Mathematical Quantum Field Theory

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…

### A First Idea of Quantum Field Theory – 20 Part Series

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

### Introduction to Perturbative Quantum Field Theory

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

### Lesson on Entanglement Entropy in Quantum Field Theory

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

### Learn About Vacuum Fluctuations in Experimental Practice

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

### Learn About Quantum Amplitudes, Probabilities and EPR

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

### Struggles with the Continuum: Spacetime Conclusion

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

### Struggles with the Continuum: General Relativity

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

### Learn the Top Misconceptions about Virtual Particles

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

### Learn the Physics of Virtual Particles in Quantum Mechanics

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…

### Struggles with the Continuum: Quantum Electrodynamics

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

### Struggles with the Continuum – Relativity and Quantum

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

### Introduction to Causal Perturbation Theory

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

### Quantum Renormalisation Made Easy

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