Formula Bose Distribution Function Probability    Energy    Chemical potential    Temperature

Probability

Unit
The occupation probability indicates with which probability $$P$$ a state with energy $$W$$ at temperature $$T$$ is occupied by a boson (for example a photon or phonon).

Energy

Unit
Energy state which can be occupied by a boson, for example by a photon or $$^4\text{He}$$ atom.

Chemical potential

Unit
Chemical potential indicates the change of internal energy when the particle number of the boson gas changes. At $$T = 0$$ the chemical potential corresponds to the Fermi energy.

Temperature

Unit
Absolute temperature of the boson gas (for example a photon gas).

Boltzmann Constant

Unit
Boltzmann constant is a natural constant, which appears more often in statistical physics and thermodynamics. It has the value: $$k_{\text B} = 1.380 \, 649 \, \cdot\, 10^{-23} \, \frac{\text J}{\text K}$$.