Hi,(adsbygoogle = window.adsbygoogle || []).push({});

I'm struggling with how to see that

[itex]\int^{L}_{0}\int^{L}_{0} \frac{dxdy}{(x-y)^2}=2L/a-2\ln{(L/a)}+\mathcal{O}(1) [/itex]

'a' here is a cutoff to avoid the divergence that occurs when x=y, I presume we just set the integrand to zero when x-y<a, I think.

Can anyone see why the above holds?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Integral with cutoff

**Physics Forums | Science Articles, Homework Help, Discussion**