Question

Can we take $\sigma^2_N=\frac{\kappa_T}{\beta V}N^2$ to be an example of the fluctuation-dissipation theorem?

Answer 1

Hey mate ^_^

Physically, the symmetrized correlator is a measure of fluctuations, and the retarded correlator is a measure of dissipation....

For example, the retarded correlator of the stress tensor determines viscosity...


#Be Brainly❤️

Answer 2

Hello mate here is your answer.

In statistical mechanics, the relation σ2E=⟨E2⟩−⟨E⟩2=kBT2CvσE2=⟨E2⟩−⟨E⟩2=kBT2Cv is interpreted ad one of the examples of fluctuation-dissipation theorem. The fluctuation in energy is directly related to the ability of the system to absorb (or dissipate) energy.

In grand canonical ensemble, one finds that the number fluctuation is given by

σ2N=⟨N2⟩−⟨N⟩2=κTβVN2.


Hope it helps you.