User Filippo

43 votes

3 answers

3k views

Do all Noether theorems have a common mathematical structure?

asked Dec 2, 2020 at 14:18

10 votes

3 answers

1k views

Why is absolute time considered an axiom of Newtonian mechanics? What statements are based on this axiom?

asked Jun 25, 2021 at 8:44

9 votes

1 answer

651 views

Spectral decomposition vs Taylor Expansion

asked Nov 30, 2020 at 12:06

8 votes

1 answer

987 views

Two different versions of Schrödinger's equation - are they equivalent?

asked Nov 7, 2020 at 17:15

8 votes

2 answers

688 views

Is the Born rule usually regarded an axiom in quantum mechanics?

asked Sep 11, 2021 at 9:46

6 votes

2 answers

140 views

$A^{\alpha}=(\phi,\vec{A})$ or $A_{\alpha}=(\phi,\vec{A})$?

asked Nov 1, 2020 at 21:26

6 votes

5 answers

710 views

How are vector quantities in three dimensions (velocity, electric field, etc.) modeled in mathematical physics?

asked Dec 4, 2020 at 15:33

5 votes

3 answers

946 views

Dirac-delta-functions as eigenbasis of the position operator - pure nonsense? Or can more be said?

asked Jan 11, 2021 at 11:06

4 votes

1 answer

215 views

A critical step in Fujikawa's proof of the Atiyah Singer index theorem

asked Apr 26, 2021 at 7:04

3 votes

2 answers

406 views

Definition of $k^0$ in Getzler's proof of the Atiyah-Singer index theorem

asked May 3, 2021 at 10:53

3 votes

2 answers

177 views

Reference request - derivation of $\mathrm{ind}\,D_+=-\frac{1}{8\pi^2}\int\text{tr}\,F\wedge F$

asked Mar 13, 2021 at 18:39

3 votes

1 answer

175 views

When and why can the spin connection term of the Dirac Operator be omitted?

asked Apr 6, 2021 at 16:36

3 votes

1 answer

785 views

Proof that conservation of momentum is Lorentz invariant

asked Aug 10, 2022 at 18:44

3 votes

2 answers

599 views

Gauge theory - definition of the trace

asked Mar 24, 2021 at 14:19

3 votes

3 answers

182 views

What is the equivalent to $\Box A^\alpha =- \mu_0 J^\alpha$ using differential forms?

asked Nov 3, 2020 at 11:29

3 votes

0 answers

194 views

HaMiDeW coefficients - recursive calculation of the coincidence limits

asked Mar 16, 2023 at 16:02

3 votes

1 answer

122 views

The inhomogeneous Maxwell equation ${}\mathrm d{}F=J^\flat$ is only true for the signature $(+---)$?

asked Nov 21, 2022 at 15:01

2 votes

3 answers

219 views

Calling angles dimensionless and simultaneously distinguishing between numbers and angles is inconsistent, isn't it?

asked Jul 30, 2022 at 21:00

2 votes

0 answers

74 views

Ising model - Two different Gibbs distributions? (Friedli-Velenik)

asked Jun 28, 2023 at 13:58

2 votes

1 answer

78 views

Differential operators in QM whose domain is a subspace of $L^2$ act on equivalence classes - How is that even defined?

asked Nov 7, 2020 at 20:54

2 votes

3 answers

222 views

Explanation of $\sum_n\langle\psi_n(x)|(O\psi_n)(x)\rangle=:(\mathrm{tr}\,O)(x)=\mathrm{tr}\int\frac{\mathrm{d}k}{(2\pi)^4}e^{ikx}Oe^{-ikx}$

asked Mar 29, 2021 at 8:53

2 votes

1 answer

74 views

I get an extra term when I try to derive $\nabla\!\!\!\!/\ ^2=\nabla_\mu \nabla^\mu+\frac{1}{4}[\gamma^\mu,\gamma^\nu]F_{\mu\nu}$

asked Mar 31, 2021 at 13:14

2 votes

1 answer

87 views

The Lorentz group is only equal to $O(1,3)$ if $c=1$?

asked Sep 13, 2022 at 19:07

2 votes

1 answer

144 views

Exponential of operators not defined on a Hilbert space (Dirac operator)

asked Apr 9, 2021 at 11:59

2 votes

3 answers

262 views

Is the equation $[\nabla_{\mu},\nabla_{\nu}]=F_{\mu\nu}$ correct? If yes, how does it have to be interpreted?

asked Mar 19, 2021 at 16:34

2 votes

1 answer

181 views

A formulation of (classical) electrodynamics using fiber bundles

asked Jun 22, 2021 at 13:26

1 vote

1 answer

73 views

Is $k_t(x,x)\sim(4\pi t)^{-n/2}\mathrm{e}^{-tF}$ if $R=0$? (Dirac operator, heat kernels)

asked Apr 29, 2021 at 8:04

1 vote

2 answers

199 views

On the proof that $4$-velocity transforms like vector

asked Sep 14, 2022 at 13:20

1 vote

1 answer

62 views

Is there a name for linear/homogeneous Galilean transformations?

asked Sep 28, 2022 at 12:16

1 vote

2 answers

177 views

Is the continuity equation used to define the current density?

asked Oct 14, 2022 at 14:03

Stack Exchange Network

47 Questions

Do all Noether theorems have a common mathematical structure?

Why is absolute time considered an axiom of Newtonian mechanics? What statements are based on this axiom?

Spectral decomposition vs Taylor Expansion

Two different versions of Schrödinger's equation - are they equivalent?

Is the Born rule usually regarded an axiom in quantum mechanics?

$A^{\alpha}=(\phi,\vec{A})$ or $A_{\alpha}=(\phi,\vec{A})$?

How are vector quantities in three dimensions (velocity, electric field, etc.) modeled in mathematical physics?

Dirac-delta-functions as eigenbasis of the position operator - pure nonsense? Or can more be said?

A critical step in Fujikawa's proof of the Atiyah Singer index theorem

Definition of $k^0$ in Getzler's proof of the Atiyah-Singer index theorem

Reference request - derivation of $\mathrm{ind}\,D_+=-\frac{1}{8\pi^2}\int\text{tr}\,F\wedge F$

When and why can the spin connection term of the Dirac Operator be omitted?

Proof that conservation of momentum is Lorentz invariant

Gauge theory - definition of the trace

What is the equivalent to $\Box A^\alpha =- \mu_0 J^\alpha$ using differential forms?

HaMiDeW coefficients - recursive calculation of the coincidence limits

The inhomogeneous Maxwell equation ${}\mathrm d{}F=J^\flat$ is only true for the signature $(+---)$?

Calling angles dimensionless and simultaneously distinguishing between numbers and angles is inconsistent, isn't it?

Ising model - Two different Gibbs distributions? (Friedli-Velenik)

Differential operators in QM whose domain is a subspace of $L^2$ act on equivalence classes - How is that even defined?

Explanation of $\sum_n\langle\psi_n(x)|(O\psi_n)(x)\rangle=:(\mathrm{tr}\,O)(x)=\mathrm{tr}\int\frac{\mathrm{d}k}{(2\pi)^4}e^{ikx}Oe^{-ikx}$

I get an extra term when I try to derive $\nabla\!\!\!\!/\ ^2=\nabla_\mu \nabla^\mu+\frac{1}{4}[\gamma^\mu,\gamma^\nu]F_{\mu\nu}$

The Lorentz group is only equal to $O(1,3)$ if $c=1$?

Exponential of operators not defined on a Hilbert space (Dirac operator)

Is the equation $[\nabla_{\mu},\nabla_{\nu}]=F_{\mu\nu}$ correct? If yes, how does it have to be interpreted?

A formulation of (classical) electrodynamics using fiber bundles

Is $k_t(x,x)\sim(4\pi t)^{-n/2}\mathrm{e}^{-tF}$ if $R=0$? (Dirac operator, heat kernels)

On the proof that $4$-velocity transforms like vector

Is there a name for linear/homogeneous Galilean transformations?

Is the continuity equation used to define the current density?