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David Ketcheson
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How can I derive a bound on the spurious oscillations in the numerical solution of the 1D advection equation?

Suppose I had the following periodic 1D advection problem:

$\frac{\partial u}{\partial t} + c\frac{\partial u}{\partial x} = 0$ in $\Omega=[0,1]$
$u(0,t)=u(1,t)$
$u(x,0)=g(x)$
where $g(x)$ has a jump discontinuity at $x^*\in (0,1)$.

It is my understanding that for linear finite difference schemes of higher than first order, spurious oscillations occur near the discontinuity as it is advected over time, resulting in a distortion of the solution from its expected wave shape. According to wikipedia explanation, it seems that these oscillations typically occur when a discontinuous function is approximated with a finite fourier series.

For some reason, I can't seem to grasp how a finite fourier series can be observed in the solution of this PDE. In particular, how can I estimate a bound on the "over-shoot" analytically?

Paul
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