Thursday, March 15, 2007

A useful integral identity

$(\int_{t}^{T}\sigma(t,u)du)^2-\int_{t}^{T}\sigma (t,u)\Sigma (t,u)du\equiv 0$ where $\Sigma (t,T)=\int_{t}^{T}\sigma(t,u)du$
This is the identity I found when I derive bond price under Q measure in the homework.

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