In this talk, we show that for a large class of ultra-differentiable potential, and for any irrational frequency, for almost every energy E the corresponding quasiperiodic Schrodinger cocycle is either rotations reducible or has positive Lyapunov exponents. This partially answers R. Krikorian's open question.  As spectral application, we prove ``Last's intersection spectrum conjecture" in the Gevrey setting.

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