quantum-field-theory

  1. The interrelation of the different forms of coupling constants

  2. Auxiliary field path integral in nonlinear sigma models

  3. Understanding renormalizability and bare mass
  4. Do spin states have a shape? If so, what are they?
  5. Can quantum particle wave functions be located on multiple points in space at once?

  6. Dirac once said that renormalization is just a stop gap procedure, and there had to occur a fundamental change in our ideas. What changed?
  7. Trying to work out the CP-transformation property of the Higgs potential

  8. One-point function and vacuum expectation value in $\phi^4$-theory
  9. Field renormalization of $\phi^4$ to second order

  10. Physical understanding of the change in scattering cross-sections at finite temperatures

  11. Is the String Field of String Field Theory the same (ontologically identical to) as the field of QFT?

  12. Solving the Klein-Gordon Equation with a Fourier Transform
  13. Funny term in my Lagrangian
  14. Temperature in the Hamiltonian limit
  15. Gauge invariance is just a redundancy. Why is massive abelian gauge field renormalizable but massive non-abelian gauge field nonrenormalizable?

  16. Getting particles from fields: normalization issue or localization issue?

  17. Spin magnetic moment direction of a particle

  18. Positive and negative energy modes of scalar field
  19. Is anti-matter matter going backwards in time?

  20. How does QFT help with entanglement?

  21. Quantum electrodynamics extended with a special topological term

  22. Random phase approximation for interacting electron gas

  23. Wick rotations, convergence and Feynman propagators?
  24. Obstruction in calculating $\mathcal{Z}_{\mathcal{N}=1}$ SYM partition function

  25. Is the reduction of tensor loop integrals to scalar integrals using Passarino Veltman Functions, theory dependent?
  26. Ordering of factors when calculating Feynman Diagrams

  27. "Dimensional analysis" arguments in quantum field theory

  28. Intuition behind mass corrections to massless fermions
  29. Connection between Hubbard-Stratonovich and (generalized) coherent states

  30. Counting Degrees of Freedom in Field Theories
  31. Dilaton coupling to CFT
  32. Cutoff-dependent "inverse propagator" for renormalization

  33. Is the Feynman propagator integrable over Minkowski spacetime?
  34. Amplitude for Spacelike Separation of Particle in QM

  35. Matter effects in neutrino oscillation
  36. Step involving delta-function in the Klein-Gordon equation solving

  37. What's the key point to argue that pure gravity can't be renormalizable from two-loop?

  38. Invariance, covariance and symmetry

  39. Why are derivatives in interaction terms treated differently from derivatives in the kinetic term?

  40. Vertex factor for $\frac{g}{4} (A_{\nu}A^{\nu})^2$ in QED

  41. Perturbative reheating after Inflation in $\phi^4$ theory

  42. Massless $m=0$ 4D Fourier transform of $(p^2 + i \epsilon)^{-2}$

  43. Klein-Gordon propagator integral in the light-like case

  44. Sakurai"s Comment Anti-particle in Klein-Gordon equation: Reversing momentum and Moving backward in time

  45. Connection between quantum field and the wavefunction

  46. What are particles if quantum fields are not physical objects?
  47. Schrodinger Wave Functional (quantum fields) - Solving Functional Gaussian Integrals

  48. Operator Product Expansion on cylinder

  49. Fourier transform and momenta flow in Feynman diagram

  50. Are the field renormalization factors infinite or finite?
  51. Transition amplitude of n-vacuua in QCD
  52. What's the geometric (or representation independent) definition of central charge of Lie algebra $\mathfrak{g}$?

  53. Bremsstrahlung and infrared divergences in Peskin & Schroeder 6.5

  54. Renormalization of a Feynman diagram with zero bare mass

  55. How is scale invariance broken in QCD?
  56. LSZ reduction theorem derivation in Weinberg QFT
  57. Homework: Feynman diagram loops, confusion about natural units
  58. How to say "speed of light is constant in all frames" in QFT?

  59. QFT Hilbert spaces over other rings than the complex numbers $\mathbb{C}$
  60. How do phase transitions really work in high energy / early universe physics?
  61. Intuitive sketch of the correspondence of a string theory to its limiting quantum field theory
  62. Why pseudoscalar can decay to photons

  63. Spin Up with Indefinite Helicity

  64. Contact terms in proof of Ward identity
  65. On the generator $K$ of boost transformation in interacting system
  66. Why is there a Cardy formula in 2d cft?

  67. Why does the integral for a "generic one-loop snail diagram" in scalar QFT blow up?

  68. How is the $\langle\psi| x(t')\, x(t)|\psi\rangle$ interpreted in the Heisenberg picture?

  69. Why are short distances synonymous with high energies?

  70. Determining Feynman rules from Lagrangian

  71. Lorentz-invariant phase space for 2->2 scattering
  72. Could the unexpectedly fast accelerating expansion of the universe be caused by the theoretical graviton's anti-particle?
  73. What does "consistent at an infinitesimal level" mean?
  74. Electrons in the nuclei
  75. Modern treatment of effective QFT in curved spacetime

  76. The relation between anomalous dimensions and renormalization constants
  77. Anomalous triangle vertex: divergencies and symmetry argument

  78. How to compute the normal ordered angular momentum of a Klein-Gordon real scalar in terms of ladder operators?
  79. Coupling $A_\mu$ to Klein Gordon equation and action?

  80. Why can the Klein-Gordon field be Fourier expanded in terms of ladder operators?
  81. Wilsonian definition of renormalizability

  82. Boson on a Torus: mode expansion
  83. Hermiticity of Dirac Operator $\gamma^{\mu}D_{\mu}$ and Expansion in eigenmodes

  84. Why don't we see macroscopic "electron waves"?

  85. Valid Bogoliubov transformation?

  86. Schwinger effect verified by Unruh temperature?

  87. Question about renormalization and parts of the Lagrangian

  88. Canonical commutation relation field theory

  89. What is the physical meaning of nilpotent operator?

  90. Srednicki QFT Chapter 29: Feynman diagrams for calculating the effective action

  91. Classical version of tree-level QFT correlation functions

  92. Physical poles in QFT scattering amplitudes?

  93. Why does the axial/chiral gamma matrix $\gamma^5$ not exist in odd dimensions?

  94. Antiparticle solution of the Dirac Equation

  95. What is an observer in QFT?
  96. What is the physical (i.e. non-mathematical) cause off the difference between a system of identical bosons and fermions?

  97. Is it possible to construct a pure Bosonic creation operator in scalar QFT?

  98. How can there be vacuum quantum fluctuations of photons if they require electric charge to "see the light"?
  99. Gupta-Bleuler and Lorenz Gauge: I don't understand the principle behind Gupta-Bleuler
  100. Gapless modes on both sides of the SFT/QFT correspondence