By using both thermal field theory and a somewhat more intuitive method , we define the electric charge as well as the charge radius of neutrinos propagating inside a plasma .
We show that electron neutrinos acquire a charge radius of order \sim 6.5 \times 10 ^ { -16 } cm , regardless of the properties of the medium .
Then , we compute the rate of plasmon decay which such an electric charge or a charge radius implies .
Taking into account the relativistic effects of the degenerate electron gas , we compare our results to various approximations as well as to recent calculations and determine the regimes where the electric charge or the charge radius does mediate the decay of plasmons .
Finally , we discuss the stellar limits on any anomalous charge radius of neutrinos .