47,317 reputation
762148
bio website arXiv.org
location Europe
age 49
visits member for 4 years, 4 months
seen 35 mins ago

I'm a theoretical physicist.


3h
comment When we ride a bicycle, why do we tend to move left when we turn it right?
Related: physics.stackexchange.com/q/24/2451
5h
comment Formulating the Lagrangian in terms of invariant quantities
Concerning Galilean symmetry of the Lagrangian, see also this related Phys.SE post.
18h
comment What is the $D_{x^2-y^2}$ symmetry/channel/instabilitied referred to with regards to super-conductivity?
Which articles?
23h
comment A question about the physics involved in tracking satellites such as those used in the GPS system
Possible duplicates: physics.stackexchange.com/q/1061/2451 and links therein.
1d
comment Derivative of effective action with respect to classical fields
Which reference are you following for sign conventions?
1d
comment Is harmonic oscillator continuous variable system?
Which literature? Which pages?
1d
comment Where does the “Supersymmetry” in Witten's proof of the Morse inequalities come from?
Related: Igor Prokhorenkov's notes found on Wikipedia.
1d
comment Where does the “Supersymmetry” in Witten's proof of the Morse inequalities come from?
Related question on MO.SE: mathoverflow.net/q/212419/13917
1d
comment Where does the “Supersymmetry” in Witten's proof of the Morse inequalities come from?
I updated the answer.
1d
comment Embedding of $F(4)$ in $OSp(8|4)$?
Minor comment to the post (v1): In the future please link to abstract pages rather than pdf files, e.g., arxiv.org/abs/0810.1484
1d
comment Quantum mechanics on a manifold
Link dead. Try here.
1d
comment Twin paradox modified for a periodic universe
Possible duplicates: physics.stackexchange.com/q/361/2451 and links therein.
2d
comment Total time derivative of magnetic vector potential $A$
Minor comment to the post (v3): Please consider to mention explicitly author, title, etc. of link, so it is possible to reconstruct link in case of link rot.
2d
comment concerning the effects of temperature and density on the speed of sound
Related: meta.physics.stackexchange.com/q/6833/2451
2d
comment Problem with OPE (from Polchinski)
Hi MaPo. If you haven't already done so, please take a minute to read the definition of when to use the homework-and-exercises tag, and the Phys.SE policy for homework-like problems.
2d
comment Is it possible to generalize the Maxwell equations to higher dimensions?
Possible duplicates: physics.stackexchange.com/q/21678/2451 , physics.stackexchange.com/q/104008/2451 and links therein.
2d
comment If time is relative, how could time pass?
Possible duplicates: physics.stackexchange.com/q/29082/2451 , physics.stackexchange.com/q/16018/2451 and links therein.
2d
comment What is the definition of potential energy?
For starters, the formula $U ~=~ -G\frac{m_1m_2}{r}+C$ has a minus, possibly an integration constant $C$, and is only valid for $r\geq R$. Possible duplicates: physics.stackexchange.com/q/18446/2451 , physics.stackexchange.com/q/2481/2451 , and links therein.
2d
comment Finding the action of a discretized Lagrangian
The question (v5) seems to be caused by a somewhat misleading exercise formulation. Exercise 17.5 (a) in QFT for the Gifted Amateur deals with a 0+1 dimensional system with Euclidean signature (where Euclidian time is called $x$), not a 1+1 dimensional system with Euclidean signature.
Jul
26
comment Noether's theorem: meaning of transformation of coordinates
It seems that both cases use horizontal transformations.