6,315 reputation
1520
bio website vladimirkalitvianski.wordpres…
location Grenoble, France
age 55
visits member for 3 years, 8 months
seen 12 mins ago

Theoretical Physicist,

A blog in Russian: http://vladimir-anski.livejournal.com/

A blog in English: http://vladimirkalitvianski.wordpress.com

Another blog in Russian: http://fishers-in-the-snow.blogspot.com


Aug
15
comment Gauge Field Tensor from Wilson Loop
Yes, it is exactly what you suspect: "Look, I have found some derivative terms $F_{\mu\nu}$ that are (gauge) invariant, now let me fiddle a bit and put its square in $\mathcal{L}$". To look convincing, you just notice that $A_{\mu}$ is a field, a filed that may have its own dynamics, so it needs a kinetic term $F^2$ in the total Lagrangian density (easy to construct). Cool? Yes, it's cool! Indeed, from just playing with some transformation properties of a free fermion field, you get a complete theory of interacting bare particles.
Aug
8
awarded  quantum-mechanics
Aug
6
awarded  Popular Question
Jun
18
comment What is an “Interaction Hamiltonian”
Lalinsky: $U$ is the interaction because without it the kinetic terms sole describe a free motion.
Jun
18
comment What is an “Interaction Hamiltonian”
And the spin-orbit interaction term, it is not an interaction Hamiltonian? There is no external thing or other physical system in it, but it is still an interaction Hamiltonian.
Jun
17
answered What is an “Interaction Hamiltonian”
Jun
17
comment What would happen if two entangled particles collided?
Entangled particles stay entangled even if they interact.
Jun
17
comment Can causality be violated?
Acausality defended in the above articles only concerns the nearest future influence on the present, i.e. it is a "little" acausality, like here youtu.be/ZbUehJJiEoE and here youtu.be/Pr38sZ4lW4M The authors say it is OK, but I don't feel comfortable with it.
Jun
17
comment Can causality be violated?
In fact, there is an acausal description, not widely accepted, still it exists in the literature. See, for example, journals.aps.org/rmp/abstract/10.1103/RevModPhys.33.37 and rand.org/content/dam/rand/pubs/research_memoranda/2006/…
Jun
16
answered What would happen if two entangled particles collided?
Jun
10
answered Can photons have negative energy?
Jun
6
comment What is the logic of not regarding perturbative renormalizability as a fundamental requirement?
@JánLalinský: I gave a brief critics of CED here, for example: vladimirkalitvianski.wordpress.com/2013/11/12/…
Jun
5
comment tritium beta decay - probability of being in 1s state
@user44840: Yes, it does, but the electron wave function under such sudden perturbation does not have time to change so the $r$-dependence remains the same at $t=0$. Then this form "evolves" as a superposition of different Helium wave functions with different energy exponentials.
Jun
5
comment What is the logic of not regarding perturbative renormalizability as a fundamental requirement?
@JánLalinský: GR is a macroscopic theory for weak fields. It does not work for point-like bodies, it has non physical singularities. It is even worse than Classical Electrodynamics in this respect.
Jun
5
comment tritium beta decay - probability of being in 1s state
@user44840: No, the electron wave function stays the same, the original one. It can be represented as a superposition of Helium wave functions. Its projection to the Helium ground state gives the amplitude to find the electron in the ground Helium state whereas the state is somewhat different in reality.
Jun
5
revised What is the logic of not regarding perturbative renormalizability as a fundamental requirement?
deleted 5 characters in body
Jun
5
revised What is the logic of not regarding perturbative renormalizability as a fundamental requirement?
added 35 characters in body
Jun
5
answered What is the logic of not regarding perturbative renormalizability as a fundamental requirement?
May
25
answered What is wrong with the Bohr model?
May
14
awarded  Popular Question