Terms
Boltzmann Factor

Any term of the form
e
^{/τ
}
is called a Boltzmann
Factor.
Gibbs Factor

Any term of the form
e
^{(Nμ)/τ
}
is called a Gibbs factor.
Gibbs Sum

The Gibbs Sum is the sum of all of the Gibbs Factors for the states and numbers of a system, and is given by:
Z
_{G}(
μ,
τ) =
e
^{(Nμ)/τ
}
Partition Function

The Partition Function represents the sum of all of the Boltzmann Factors for the states of a system, and is given by:
Z =
e
^{/τ
}
Planck distribution function

The Planck distribution function describes the average number of photons
< s >
in a particular frequency
σ
for blackbody radiation and is given by:
<
s > =
StefanBoltzmann law of radiation

The StefanBoltzmann law of radiation gives the energy density of radiation in a cavity, as can be expressed:
=
τ
^{4}
Formulae
The probability of finding a system in energy state
if the system is in thermal contact with a reservoir

P( ) =

The entropy of blackbody radiation

σ = ( ) ^{3}
