How do you measure numerically central charge of the system ?

[Murtuza Tipu]

Let's say that you are doing some Monte-Carlo simulations of a statistical system on a lattice and you observe scale invariance, meaning that you are at a conformal point. Can you get a numerical appreciation of the central charge?

I know how the central charge is related on the free energy (on a cylinder for example) or to the stress-energy tensor but these are not direct observable in a Monte-Carlo.

Is there a systematic method for that? Has it already been done?

 

[alionalizoti]

Measuring electrostatic charge

Well, theoretical suggestions are as many;
but lab techniques suggest for scaled electroscopes to do as such.
There also are technical issues

Measuring the q charge - contacting method
1) Sure one has to contact the "point" charge with the top head of the electroscope.
2) The scale has to agree with the physical systems of measurements, SI or else.

Measuring the V potential capabilities - induction method
1) Sure one has to keep the "point" charge at several distances with the top head of the electroscope.
2) The scale has to agree with the physical systems of measurements, SI or else.

 

[Murtuza Tipu]

Well, theoretical suggestions are as many;
but lab techniques suggest for scaled electroscopes to do as such.
There also are technical issues

Measuring the q charge - contacting method
1) Sure one has to contact the "point" charge with the top head of the electroscope.
2) The scale has to agree with the physical systems of measurements, SI or else.

Measuring the V potential capabilities - induction method
1) Sure one has to keep the "point" charge at several distances with the top head of the electroscope.
2) The scale has to agree with the physical systems of measurements, SI or else.

Is you answer about measuring an electric charge? I'm interested in 'measuring' numerically the central charge which is a number characterizing a conformal field theory.

 

[alionalizoti]

Measuring the charge

Of course, I mean measuring the electrostatic charge,
which sure be at the center of any net field or field net, whatever!
( any means theoretical or experimental )