# Tag Info

## New answers tagged chemical-potential

2

If in your system the number of of photons is non conserved, the Gibbs free energy cannot depend on the number of photons. So you will have $$\mu_{\gamma}=\left(\frac{\partial G}{\partial N_{\gamma}}\right)_{T,P}=0$$ This also implies that $\mu_{matter}+\mu_{\gamma}=\mu_{matter}$. However, in systems that conserve the number of photons, you return to the ...

Top 50 recent answers are included