Unanswered Questions
109
votes
1answer
7k views
Superfields and the Inconsistency of regularization by dimensional reduction
Question:
How can you show the inconsistency of regularization by dimensional reduction in the $\mathcal{N}=1$ superfield approach (without reducing to components)?
Background and some references:
...
70
votes
1answer
3k views
Experimental test of the non-statisticality theorem?
Context: The paper On the reality of the quantum state (Nature Physics 8, 475–478 (2012) or arXiv:1111.3328) shows under suitable assumptions that the quantum state cannot be interpreted as a ...
47
votes
1answer
2k views
On the Coulomb branch of ${\cal N}=2$ supersymmetric gauge theory
The chiral ring of the Coulomb branch of a 4D ${\cal N}=2$ supersymmetric gauge theory is given by the Casimirs of the vector multiplet scalars, and they don't have non-trivial relations; the Casimirs ...
41
votes
0answers
2k views
Linear sigma models and integrable systems
I'm a mathematician who recently became very interested in questions related to mathematical physics but somehow, I already have difficulties in penetrating the literature... I'd highly appreciate any ...
37
votes
1answer
575 views
Systematic approach to deriving equations of collective field theory to any order
The collective field theory (see nLab for a list of main historical references) which came up as a generalization of the Bohm-Pines method in treating plasma oscillations are often used in the study ...
36
votes
0answers
1k views
Orbits of maximally entangled mixed states
It is well known (Please, see for example Geometry of quantum states by Bengtsson and Życzkowski ) that the set of $N$-dimensional density matrices is stratified by the adjoint action of $U(N)$, where ...
33
votes
1answer
2k views
Status of experimental searches for tachyons?
Now that the dust has settled on the 2011 superluminal neutrino debacle at OPERA, I'm interested in understanding the current status of experimental searches for neutrinos. Although the OPERA claim ...
32
votes
2answers
761 views
Has Jaynes's argument against Bell's theorem been debunked?
As a student of theoretical physics I'm well acquainted with the multitude of crackpot ideas attempting to circumvent Bell's theorem regarding local hidden variable theories in quantum physics.
...
31
votes
0answers
1k views
Are the fast axes on Thorlabs quarter-waveplates mislabeled?
Some members of my lab are performing a polarization-sensitive experiment where they need to use a quarter-waveplate (QWP) with the fast axis in a specific direction. In the process of carefully ...
30
votes
0answers
953 views
Is the Hawking radiation of a charged black hole thermal?
Suppose you have a Schwarzschild black hole of mass $M$ and angular parameter $a = 0$ (no rotation).
Question: is it possible to throw a charge $Q$ at a faster rate than it will be re-radiated? Will ...
26
votes
0answers
816 views
Can Lee-Yang zeros theorem account for triple point phase transition?
Now the prominent Lee-Yang theorem (or Physical Review 87, 410, 1952) has almost become a standard ingredient of any comprehensive statistical mechanics textbook.
If the volume tends to infinity, ...
23
votes
1answer
2k views
Motivation for the use of Tsallis entropy
Every now and again I hear something about Tsallis entropy,
$$
S_q(\{p_i\}) = \frac{1}{q-1}\left( 1- \sum_i p_i^q \right), \tag{1}
$$
and I decided to finally get around to investigating it. I haven't ...
22
votes
1answer
761 views
Vibrational anharmonic coupling and noise-induced spontaneous symmetry breaking in a hexagonal finite mechanical lattice
Happy holidays, everyone! The following is part question, part visual gallery, and part classical mechanics problem. Inspired by snow over the weekend I began simulating the vibrations of the ...
21
votes
0answers
880 views
What different approximations yield Gravitoelectromagnetism and Weak Field Einstein Equations?
This question is inspired by this answer, which cites Gravitoelectromagnetism (GEM) as a valid approximation to the Einstein Field Equations (EFE).
The wonted presentation of gravitational waves is ...
21
votes
1answer
352 views
Fluctuations of an interface with hammock potential
This question is related to that one. I ask it here since comments are too short for the extended discussion that was going on there.
I am interested in a very simple interface model. To each $x\in\...
