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12 votes

Terminology confusion - "particle"

answered Oct 4, 2017 at 9:22

9 votes

Are there really left-chiral particles?

answered Dec 9, 2014 at 10:15

8 votes

Why the extra term $\frac{1}{2}(\partial_{\rho}A^{\rho})^2$ in the photon Lagrangian?

answered Nov 18, 2014 at 11:40

8 votes

Accepted

Physical interpretation of gamma matrices

answered Nov 19, 2019 at 15:02

7 votes

Why Lie algebras if what we care about in physics are groups?

answered Jul 25, 2019 at 9:21

6 votes

Accepted

Two conflicting definitions of chirality

answered Apr 21, 2016 at 6:14

5 votes

Retarded and advanced Green's function and Feynman propagator

answered Oct 29, 2019 at 12:51

5 votes

Calculus of variations -- how does it make sense to vary the position and the velocity independently?

answered Dec 29, 2019 at 9:53

4 votes

Accepted

Lorentz transformation and symmetries of the Lagrangian

answered Jun 2, 2016 at 9:09

4 votes

Group theoretical reason that Gluons carry color-charge and anti-colorcharge

answered Oct 10, 2014 at 20:15

4 votes

Gluon have colour-anticolour; what about weak bosons?

answered Jul 12, 2015 at 9:51

4 votes

Invariance of canonical Hamiltonian equation when adding the total time derivative of a function of $q_i$ and $t$ to the Lagrangian

answered Mar 3, 2019 at 15:14

4 votes

Temperature and Renormalization Scale in QFT

answered Jul 3, 2017 at 8:05

3 votes

Rotational symmetry $\leftrightarrow$ isotropy, dilation symmetry $\leftrightarrow$ ________?

answered Oct 4, 2018 at 14:17

3 votes

Accepted

What's the difference between a generating function and a generator?

answered Feb 21, 2019 at 11:38

3 votes

Are terms with spinors analogous to $ ( \partial_\mu \Phi )(\partial^\mu \Phi)$ forbidden in the Lagrangian?

answered Nov 19, 2014 at 9:13

3 votes

What are the six quark mass values when extrapolated to Planck energy?

answered Feb 19, 2016 at 14:13

3 votes

Why do we need to renormalize in QFT, really?

answered Jul 5, 2019 at 7:48

2 votes

Prove that Noether's Theorem produces generators of the symmetry

answered Feb 16, 2019 at 12:21

2 votes

What's the intuitive reason that phase space flow is incompressible in Classical Mechanics but compressible in Quantum Mechanics?

answered Jul 5, 2018 at 7:22

1 vote

About Lorentz Group

answered Mar 25, 2015 at 11:43

1 vote

What happens to the global $U(1)$ symmetry in alternative formulations of Quantum Mechanics?

answered Feb 6, 2019 at 13:50

1 vote

Canonical transformations preserve Hamilton's equations. Which transformation preserve the Euler-Lagrange equations?

answered Feb 21, 2019 at 12:44

1 vote

How does the Hamiltonian change if $L\to L + \frac{dF}{dt}$?

answered Mar 3, 2019 at 14:00

1 vote

What does $\frac{d\rho}{dt} =0$ but $\frac{\partial \rho}{\partial t} \neq 0 $ mean intuitively?

answered Mar 6, 2019 at 15:34

1 vote

What justifies the use of asymptotic momentum state?

answered Oct 25, 2019 at 14:51

1 vote

Motivation for usage of 4-vectors in special relativity

answered May 3, 2016 at 12:45

1 vote

Why and how is the speed of light in vacuum constant, i.e., independent of reference frame?

answered Dec 10, 2016 at 8:26

1 vote

Accepted

Dirac spinor and Lorentz group

answered Nov 19, 2019 at 15:08

0 votes

Is there some truth to the often told story that the running of couplings is the result of screening through virtual particles?

answered Nov 20, 2019 at 8:56

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43 Answers

Terminology confusion - "particle"

Are there really left-chiral particles?

Why the extra term $\frac{1}{2}(\partial_{\rho}A^{\rho})^2$ in the photon Lagrangian?

Physical interpretation of gamma matrices

Why Lie algebras if what we care about in physics are groups?

Two conflicting definitions of chirality

Retarded and advanced Green's function and Feynman propagator

Calculus of variations -- how does it make sense to vary the position and the velocity independently?

Lorentz transformation and symmetries of the Lagrangian

Group theoretical reason that Gluons carry color-charge and anti-colorcharge

Gluon have colour-anticolour; what about weak bosons?

Invariance of canonical Hamiltonian equation when adding the total time derivative of a function of $q_i$ and $t$ to the Lagrangian

Temperature and Renormalization Scale in QFT

Rotational symmetry $\leftrightarrow$ isotropy, dilation symmetry $\leftrightarrow$ ________?

What's the difference between a generating function and a generator?

Are terms with spinors analogous to $ ( \partial_\mu \Phi )(\partial^\mu \Phi)$ forbidden in the Lagrangian?

What are the six quark mass values when extrapolated to Planck energy?

Why do we need to renormalize in QFT, really?

Prove that Noether's Theorem produces generators of the symmetry

What's the intuitive reason that phase space flow is incompressible in Classical Mechanics but compressible in Quantum Mechanics?

About Lorentz Group

What happens to the global $U(1)$ symmetry in alternative formulations of Quantum Mechanics?

Canonical transformations preserve Hamilton's equations. Which transformation preserve the Euler-Lagrange equations?

How does the Hamiltonian change if $L\to L + \frac{dF}{dt}$?

What does $\frac{d\rho}{dt} =0$ but $\frac{\partial \rho}{\partial t} \neq 0 $ mean intuitively?

What justifies the use of asymptotic momentum state?

Motivation for usage of 4-vectors in special relativity

Why and how is the speed of light in vacuum constant, i.e., independent of reference frame?

Dirac spinor and Lorentz group

Is there some truth to the often told story that the running of couplings is the result of screening through virtual particles?