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$$
{\frac  {P_{{\mathrm  {rad}}}}{A_{{\mathrm  {F}}}}}={\biggl (}{\frac  {T^{4}}{3}}{\biggr )}{\frac  {a_{{\mathrm  {rad}}}}{A_{{\mathrm  {F}}}}}={\biggl (}{\frac  {T^{4}}{3}}{\biggr )}{\frac  {8\pi ^{5}}{15}}{\frac  {k^{4}}{(hc)^{3}}}{\frac  {3h^{3}}{\pi m_{e}^{4}c^{5}}}={\frac  {8\pi ^{4}}{15}}{\biggl (}{\frac  {T}{T_{e}}}{\biggr )}^{4}.
$$
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