2,265 reputation
419
bio website azimuthproject.org/azimuth/…
location Munich, Germany
age 39
visits member for 3 years, 8 months
seen Jun 20 '13 at 19:28

I'm a physics graduate working as an IT-developer and -consultant.


Feb
2
comment Is a periodic force capable of transporting a particle to large distances?
IS there some nontrivial potential present?
Feb
2
answered Shaking a jar of balls
Feb
2
comment How to explain the weak force to a layman?
I don't know that many "laymen" who are familiar with the picture that EM forces come from the exchange of virtual photons :-)
Feb
2
comment How to explain the weak force to a layman?
Is there a specific reason why the modern picture of the weak force is harder to explain than the other forces?
Feb
2
comment How to calculate the volume of water from the measured rainfall?
I have to a gree that this is not a question about physics, not even about meteorology in a broader sense, therefore I'm voting to close.
Feb
1
comment Formalization (and meaning) of Heisenberg Cut
@Peter Morgan: The "state" in AQFT is an appropriate state of a net of operator algebras, it is not a state in the sense of pre-QM physics. The measurement process itself is not formalized in AQFT, AQFT stops with the statement "the expectation value of an observable x in a state y is...", which is a purely quantum concept. Of course the concepts of states and measurements did exist in pre-QM physics, but AQFT is not a "quantized" classical theory like e.g. Lagrangian QFT. There is no a priori given classical theory.
Feb
1
comment Formalization (and meaning) of Heisenberg Cut
@Roy: I'd draw the line and say that everything that phycisists calculate in QM with a formalized, mathematical framework does not have any connection to any concept like the Heisenberg cut. This concept is addressed, however, by people working on the philosophical interpretation of QM like Omnes.
Feb
1
answered Formalization (and meaning) of Heisenberg Cut
Feb
1
comment Diff(M) as a gauge group and local observables in theories with gravity
What about the event that a detector makes "ping" because it detects a particle (i.e. a sharply localized excitation of the appropriate quantum field)? Isn't this a local event that all observers will agree upon?
Feb
1
revised Diff(M) as a gauge group and local observables in theories with gravity
added 661 characters in body
Feb
1
comment Diff(M) as a gauge group and local observables in theories with gravity
Sure, why not, I linked to the "Diff(M)" part because I agree with Streater on this one and did not want to repeat what he wrote. (I also happen to agree with him on the other points, but that's not important for the question at hand :-)
Feb
1
awarded  Student
Feb
1
comment Other possible theories (other than string theory) which are generalizations of the standard model with incorporation of gravity
Your question is about a topic that has seen broad and sometimes violate discussions over the last 10 years, with tons of papers and hundreds of participants. Therefore I don't think that this question can be appropriatly handled on this site.
Feb
1
asked Diff(M) as a gauge group and local observables in theories with gravity
Feb
1
comment Is the S-Matrix the only quantum field observable?
@Peter: It's not a matter of being generous :-) Sorry, I don't understand "Everybody except Particle Physicists happily measure Wightman/correlation functions". Particle physicists use detectors, which are modeled in AQFT by almost localized observables, which is then an observable that is of interest and is not associated to the S-matrix (see the paper I mentioned).
Feb
1
comment Is the S-Matrix the only quantum field observable?
@Carl Brannan: Yes, but one can also define a charge operator in cases where there is no S-matrix
Jan
31
answered Is the S-Matrix the only quantum field observable?
Jan
31
comment Modes of a QFT and irreducible representation of the gauge group
Maybe I'm missing something obvious but don't physical states in a gauge theory always have to be gauge invariant?
Jan
31
comment Studying electrodynamics problems
Is it to be understood that the students you have in mind are fluent with classical vector analysis and its integral theorems? (The classical versions of the general Stoke's theorem?)
Jan
31
awarded  Commentator