Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Geometry Effect on Black Body Radiation with Different Boundary
  Conditions   We study the black body radiation in cavities of different geometry with
different boundary conditions, and the formulas of energy spectral densities in
films and rods are obtained, also the approximate energy spectral densities in
cubic boxes are calculated. We find that the energy spectral densities deviate
from Planck's formula greatly when the length(s) at some directions of the
cavity can be compared to the typical wavelengths of black body radiation in
infinite volume and the boundary conditions also affect the results. We obtain
an asymptotic formula of energy spectral density for a closed cavity with
Dirichlet boundary condition and find it still fails when the size of the
cavity is too small.

36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an