Abstract:
We conjecture that the Garsia entropy coincides with the entropy of the invariant
multidimensional Erdös measure. This conjecture is true for all Garsia numbers. We also
specify the algebraic unit being non-Pisot number, for which this conjecture is true.
We prove a theorem, which generalizes the Garsia theorem on the absolute continuity of
the infinite Bernoulli convolution for the Garsia numbers. The proof uses relations between
the multidimensional Erdös problem and the one-dimensional Erdös problem.
We discuss a connection between the entropy of the invariant Erdös measure and the
conditional Ledrappier–Young entropies. We also formulate three conjectures and obtain
some consequences from them. In particular, we conjecture that the Hausdorff dimension of
the Erdös measure is equal to the Ledrappier–Young dimension of conditional measure for
the multidimensional invariant Erdös measure along the unstable foliation corresponding to
the top Lyapunov exponent of multiplicity 1. For 2-numbers, we obtain formulae for the
Hausdorff dimension of Erdös measures on the unstable plane.
Keywords:Garsia entropy, Hausdorff dimension of the measure, Erdös measure, Hochman formula, Lyapunov exponent.