For 10 points, name this quantity measured in kelvins.
The Lorenz number equals the ratio of two material-dependent constants times the inverse of this quantity according to the Wiedemann-Franz Law. A correction of alpha times this quantity squared over beta plus this quantity is applied to the band gap energy in Varshni's equation. The ratio of perpendicular electric and magnetic fields divided by the (*) gradient in this quantity gives the magnitude of an effect named for Ettingshausen and Nernst. Population inversion generates an unusually negative value for this quantity. A junction with different types of conductor with different values of this quantity generates EMF in the Seebeck effect. Wien's law inversely relates the peak wavelength of blackbody radiation to this quantity, explaining why the brightest main sequence stars are blue. For 10 points, name this quantity measured in kelvins.
The Lorenz number equals the ratio of two material-dependent constants times the inverse of this quantity according to the Wiedemann-Franz Law.
Temperature [prompt on T]