User schris38

13 votes

2 answers

873 views

Basic Facts about Lie Algebras

asked Jun 14 at 11:55

8 votes

1 answer

123 views

Why the Feynman diagrams contributing to the effective action $\Gamma[\phi_{\rm cl}]$ are stripped/amputated/have no external lines?

quantum-field-theory feynman-diagrams correlation-functions propagator 1pi-effective-action

asked Feb 11 at 9:43

6 votes

3 answers

146 views

Local gauge transformations and Noether Current

electromagnetism lagrangian-formalism gauge-theory noethers-theorem gauge-invariance

asked Jul 1 at 15:01

5 votes

1 answer

128 views

Renormalization conditions on $\phi^4$ theory

quantum-field-theory renormalization

asked Feb 7 at 9:52

5 votes

1 answer

83 views

Conserved charge at null infinity associated with Large gauge transformation

electromagnetism general-relativity gauge-invariance research-level locality

asked May 11 at 20:16

4 votes

1 answer

122 views

Symmetry implies Ward identity

quantum-field-theory symmetry s-matrix-theory ward-identity

asked May 12 at 7:27

4 votes

1 answer

102 views

Virtual soft photon exponentiation

quantum-field-theory quantum-electrodynamics renormalization virtual-particles infrared-radiation

asked May 22 at 13:30

3 votes

0 answers

128 views

Faddeev - Kulish paper questions

quantum-field-theory quantum-electrodynamics renormalization research-level infrared-radiation

asked May 22 at 13:59

3 votes

1 answer

108 views

Question about field configurations on the boundary of $\mathcal{I}^+$

quantum-field-theory renormalization research-level infrared-radiation asymptotics

asked May 22 at 17:27

3 votes

1 answer

95 views

The Faddeev-Popov generating functional and its independence on the gauge-fixing function

quantum-field-theory gauge-theory quantum-electrodynamics path-integral gauge

asked Jun 23 at 13:54

3 votes

1 answer

119 views

On the Ward Identity in QED

quantum-field-theory gauge-theory quantum-electrodynamics gauge-invariance ward-identity

asked Jun 29 at 11:36

3 votes

2 answers

284 views

BRST Symmetry and Single Particle States

quantum-field-theory gauge-theory yang-mills brst ghosts

asked Jul 25 at 7:53

3 votes

0 answers

55 views

Decomposition of the Photon Propagator into $K$ and $G$ propagators

quantum-field-theory quantum-electrodynamics renormalization research-level infrared-radiation

asked Aug 4 at 12:41

3 votes

2 answers

76 views

Invariants of inner product in pseudoreal representation of $SU(2)$

group-theory representation-theory spinors

asked Jun 10 at 10:51

3 votes

1 answer

46 views

Subleading soft theorem and gauge invariance

quantum-field-theory quantum-electrodynamics renormalization research-level infrared-radiation

asked May 22 at 13:03

3 votes

1 answer

146 views

In and out states of scattering in Asymptotically flat spacetimes

general-relativity quantum-electrodynamics scattering qft-in-curved-spacetime asymptotics

asked May 10 at 20:19

3 votes

1 answer

81 views

Propagator in Large Momentum Shell - Renormalization Group

quantum-field-theory renormalization path-integral propagator effective-field-theory

asked Feb 21 at 14:16

3 votes

0 answers

93 views

QED Soft Theorems and Momentum Conserving $\delta$ function

quantum-field-theory electromagnetic-radiation research-level s-matrix-theory infrared-radiation

asked Jan 19 at 16:21

2 votes

1 answer

116 views

Fock Space and Coherent state

quantum-field-theory hilbert-space many-body quantum-states coherent-states

asked May 4 at 6:41

2 votes

2 answers

112 views

Greens Functions in Birrell and Davies "QFT in Curved Space" book

quantum-field-theory greens-functions qft-in-curved-spacetime

asked Aug 5 at 14:41

2 votes

1 answer

54 views

Renormalization and virtual soft divergences

quantum-field-theory quantum-electrodynamics renormalization scattering

asked May 28 at 15:58

2 votes

1 answer

54 views

Summing over zero mode energies

quantum-field-theory renormalization qft-in-curved-spacetime

asked Jul 7 at 15:59

2 votes

1 answer

100 views

Applying the Optical Theorem in Non-Abelian Gauge Theories

quantum-field-theory gauge-theory gauge-invariance unitarity ghosts

asked Jul 15 at 9:12

2 votes

1 answer

71 views

Green Function expressed in terms of Hankel function (of the second kind)

quantum-field-theory greens-functions propagator qft-in-curved-spacetime special-functions

asked Jul 15 at 14:52

1 vote

1 answer

93 views

Faddeev-Kulish Asymptotic Dynamics Question

quantum-mechanics quantum-field-theory quantum-electrodynamics research-level

asked Apr 12 at 14:19

1 vote

1 answer

84 views

Momentum integral yielding $\delta$ function

fourier-transform integration dirac-delta-distributions research-level infrared-radiation

asked Apr 19 at 7:15

1 vote

0 answers

46 views

State time-evolution in the Interaction picture

quantum-mechanics quantum-field-theory hilbert-space time-evolution s-matrix-theory

asked Apr 20 at 11:42

1 vote

0 answers

42 views

Momentum Conserving Delta Function and Soft Gravitons

quantum-field-theory quantum-gravity polarization gauge-invariance research-level

asked Jan 23 at 11:10

1 vote

0 answers

33 views

Photon Emission by Massless Fermions and Direction of Motion

quantum-field-theory angular-momentum quantum-spin quantum-electrodynamics photon-emission

asked Jan 4 at 17:04

1 vote

1 answer

95 views

Fourier transformed functional integral

quantum-field-theory fourier-transform path-integral

asked Feb 18 at 9:42

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32 Questions

Basic Facts about Lie Algebras

Why the Feynman diagrams contributing to the effective action $\Gamma[\phi_{\rm cl}]$ are stripped/amputated/have no external lines?

Local gauge transformations and Noether Current

Renormalization conditions on $\phi^4$ theory

Conserved charge at null infinity associated with Large gauge transformation

Symmetry implies Ward identity

Virtual soft photon exponentiation

Faddeev - Kulish paper questions

Question about field configurations on the boundary of $\mathcal{I}^+$

The Faddeev-Popov generating functional and its independence on the gauge-fixing function

On the Ward Identity in QED

BRST Symmetry and Single Particle States

Decomposition of the Photon Propagator into $K$ and $G$ propagators

Invariants of inner product in pseudoreal representation of $SU(2)$

Subleading soft theorem and gauge invariance

In and out states of scattering in Asymptotically flat spacetimes

Propagator in Large Momentum Shell - Renormalization Group

QED Soft Theorems and Momentum Conserving $\delta$ function

Fock Space and Coherent state

Greens Functions in Birrell and Davies "QFT in Curved Space" book

Renormalization and virtual soft divergences

Summing over zero mode energies

Applying the Optical Theorem in Non-Abelian Gauge Theories

Green Function expressed in terms of Hankel function (of the second kind)

Faddeev-Kulish Asymptotic Dynamics Question

Momentum integral yielding $\delta$ function

State time-evolution in the Interaction picture

Momentum Conserving Delta Function and Soft Gravitons

Photon Emission by Massless Fermions and Direction of Motion

Fourier transformed functional integral