Results of the Photon Wave Equation in n dimensions

Only results and calculation formulas are shown on this page. You can find the derivations for them and other useful sources on the bottom of this page.

1-D Wave Equation

2-D Wave Equation

3-D Wave Equation

Calculation formula

Eigenfunction
solutions

-

Dispersion relation

-

Density of states, D(k)

Density of states, D(ω)

Density of states, D(λ)

Density of states, D(E)

Intensity distribution, I(λ)

Wien's law

Stefan - Boltzmann law

Internal energy distribution, u(λ)

Internal energy

Helmholtz free energy

Entropy

Specific heat

Pressure

 c = velocity of propagation. Photons: c = 299792458 m/s.
 u = wave function.
 k = wave number.
= wave vector.
 Ω = the wave's frequency.
 p = number of polarizations. Photons: p = 2, Phonons: p = 3.
= the area of the surface in reciprocal space (k-space) with given k.
 Vrez = the volume of the brillouin zone in the reciprocal space.
.
 V = volume of our box.
.
 λ = wavelength.
 E = energy.
 h = Planck constant. h = 6.62606896E-34 Js.
= reduced Planck constant.
.
 kB = Boltzmann constant. kB = 1.3806504E-23 J/K.
= the vector pointing out of the infinitesimally small area dA.
 ΩR = the solid angle of the space. In 3D, ΩR = 4π.
 ΩR/2 = the solid angle of the half-space.
= the unitary vector pointing in the direction specified by Ω.
 λmax = the peak wavelength of the intensity.
 T = temperature.
.
 ζ(s) = the Riemann Zeta function.

Links you might find interesting

How to derive these results
Wikipedia article about the Stefan Boltzmann law
Wikipedia article about Planck's Black Body radiation law
The Bose-Einstein distribution in short
German Wikipedia article containing formulas on Planck's Black Body radiation law
German Wikipedia article about Planck's Black Body radiation law