- #1
telegraphic
- 3
- 0
Hi all -- I had a question about the Nyquist-Johnson noise formula:
[itex]
\[
E_{\nu}^{2}d\nu=\frac{4R_{\nu}hd\nu}{e^{h\nu/kT}-1}\]
[/itex]
which of course can be approximated for most purposes as [itex]$ E_{\nu}^{2}d\nu=4R_{\nu}kTd\nu$[/itex].
I'm just wondering why the formula has [itex]$ exp(h\nu/kT)-1$[/itex] in the denominator? I would have expected [itex]$ exp(h\nu/kT)+1$[/itex] as electrons are fermions, so obey Fermi-Dirac statistics as opposed to Bose-Einstein. Sure I'm missing something obvious!
Cheers
[itex]
\[
E_{\nu}^{2}d\nu=\frac{4R_{\nu}hd\nu}{e^{h\nu/kT}-1}\]
[/itex]
which of course can be approximated for most purposes as [itex]$ E_{\nu}^{2}d\nu=4R_{\nu}kTd\nu$[/itex].
I'm just wondering why the formula has [itex]$ exp(h\nu/kT)-1$[/itex] in the denominator? I would have expected [itex]$ exp(h\nu/kT)+1$[/itex] as electrons are fermions, so obey Fermi-Dirac statistics as opposed to Bose-Einstein. Sure I'm missing something obvious!
Cheers