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2d
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2d
comment Strain-Displacement relationship symmetrization
but it is a quantity that in principle can be different at different points of the solid
Oct
21
comment Strain-Displacement relationship symmetrization
so they can be interpreted as a rigid rotation strain?
Oct
21
comment Strain-Displacement relationship symmetrization
but in this case the anti-symmetric components of displacements are in principle invariant under such relabeling or axis reorientation. The anti-symmetric component of a 3x3 matrix transforms as an axial vector
Oct
21
comment Strain-Displacement relationship symmetrization
you are referring to the Voigt notation: en.wikipedia.org/wiki/Voigt_notation
Oct
21
comment Strain-Displacement relationship symmetrization
can you point a reference for this and elaborate a bit?
Oct
21
asked Strain-Displacement relationship symmetrization
Oct
8
asked Does a superconductor spinning in a magnetic field radiate?
Oct
2
accepted Beads flying out of flask
Oct
1
asked Beads flying out of flask
Sep
25
comment What is the highest frequency directly detected?
What would you say qualifies as a 'direct' detection? a waveform in an oscilloscope?
Sep
25
awarded  Popular Question
Sep
18
comment Detecting negative energy products in particle accelerators
It seems that the interesting case that hasn't been clarified in my mind is when the negative-energy particle is detected, but it is mistaken by a regular positive-energy particle. So the next question I'm going to do is to resolve this aspect. I'll write it up and post it later, probably tomorrow. Thanks for your help Anna!
Sep
18
comment Detecting negative energy products in particle accelerators
Ok I see it now, if you write the missing energy in terms of missing momenta (the non-squared magnitude, so not to lose the sign of the rest mass), the condition $$ \sum_f{E_f} - E_i < c \Big|\Big|P_i - \sum_f{P_f}\Big|\Big| $$ (which is a tachyonic end-product would be easier to detect than the condition for negative-energy end-product (which is $\sum_f{E_f} - E_i < 0$). Is this correct?
Sep
18
comment Detecting negative energy products in particle accelerators
I see what the problem is - a null or nearly-null negative energy particle will have momentum pointing somewhere, so the way to detect these is by inspecting apparent violations of transverse momentum.. unless the detectors can tell in what direction momentum is on a given trajectory, if the detector assumes the momentum is always pushing forward, then it can't possibly detect such anomalies, even if they are happening. Maybe they could be mistaken by neutrinos
Sep
17
accepted Detecting negative energy products in particle accelerators
Sep
17
comment Detecting negative energy products in particle accelerators
I'm not sure what tachyons have to do with this, I presume that was a typo and you actually meant 'negative-energy quanta'. But I agree with the fact that no output energy greater than unity has been measured on the observed end states is suggestive that no negative-energy on-shell quanta is among the end products. So I take this as an acceptable answer to my question (for now, at least)
Sep
16
comment Detecting negative energy products in particle accelerators
also, since you mentioned MonteCarlo programs, I'm also interested in a MonteCarlo simulation that shows specifically what to expect on the detectors if a negative-energy gamma photon would hit it. I'm considering learning Geant if required
Sep
16
comment Detecting negative energy products in particle accelerators
gammas are photons, I agree. Can we measure or infer the sign of their time-like component of four-momentum? can you elaborate on this, please?
Sep
16
revised Detecting negative energy products in particle accelerators
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