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Amanda de Lima

Publications and source records attributed to Amanda de Lima.

3 recordsLinked to original sources

Central limit theorem for generalized Weierstrass functions

Let $f$ be a $C^{2+ε}$ expanding map of the circle and $v$ be a $C^{1+ε}$ real function of the circle. Consider the twisted cohomological equation $v(x) = α(f(x)) - Df(x) α(x)$ which has a unique bounded solution $α$. We prove that $α$ is either $C^{1+ε}$ or nowhere differentiable, and if $α$ is nowhere differentiable then the Newton quotients of $α$, after an appropriated normalization, converges in distribution to the normal distribution, with respect to the unique absolutely continuous invariant probability of $f$.

math.DS

On infinitely cohomologous to zero observables

We show that for a large class of piecewise expanding maps T, the bounded p-variation observables u_0 that admits an infinite sequence of bounded p-variation observables u_i satisfying u_i(x)= u_{i+1}(Tx) -u_{i+1}(x) are constant. The method of the proof consists in to find a suitable Hilbert basis for L^2(hm), where hm is the unique absolutely continuous invariant probability of T. In terms of this basis, the action of the Perron-Frobenious and the Koopan operator on L^2(hm) can be easily understood. This result generalizes earlier results by Bamon, Kiwi, Rivera-Letelier and Urzua in the case T(x)= n x mod 1, n in N-{0,1} and Lipchitizian observables u_0.

math.DS