= Singular initial market-price-of-risk obstruction
{title2=$\int_0^\delta\lambda_t^2dt=\infty$}
A positive normalized continuous <local martingale deflator> requires a locally square-integrable Brownian diffusion coefficient. If the forced <market price of risk> is $-t^{-1/2}$, the coefficient has magnitude $Z_t/\sqrt t$. Since $Z_0>0$, continuity makes its squared integral diverge near zero. The bank account can nevertheless exist because $t^{-1/2}$ itself is integrable; finite integrated interest is weaker than square-integrability of the required risk compensation.
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