Galloping instability of viscous shock waves

This is joint work with Kevin Zumbrun (Indiana University). Motivated by physical and numerical observations of time oscillatory galloping, spinning, and cellular instabilities of detonation waves, we study Poincare--Hopf bifurcation of traveling-wave solutions of viscous conservation laws. The main difficulty is the absence of a spectral gap between oscillatory modes and essential spectrum, preventing standard reduction to a finite-dimensional center manifold. We overcome this by direct Lyapunov--Schmidt reduction, using detailed pointwise bounds on the linearized solution operator.