2011/09/05 by Bond, Matthew, Laba, Izabella, Volberg, Alexander · 3 citations
#Classical Analysis and ODEs (math.CA) #FOS: Mathematics
paper · doi:10.48550/arxiv.1109.1031
Let S_∞=A_∞× B_∞ be a self-similar product Cantor set in the complex plane, defined via S_∞=\bigcupj=1L Tj(S_∞), where Tj:\C→\C have the form Tj(z)=\frac1Lz+zj and \z1,...,zL\=A+iB for some A,B⊂\rr with |A|,|B|>1 and |A||B|=L. Let SN be the L-N-neighbourhood of S_∞, or equivalently (up to constants), its N-th Cantor iteration. We are interested in the asymptotic behaviour as N→∞ of the \it Favard length of SN, defined as the average (with respect to direction) length of its 1-dimensional projections. If the sets A and B are rational and have cardinalities at most 6, then the Favard length of SN is bounded from above by CN-p/loglog N for some p>0. The same result holds with no restrictions on the size of A and B under certain implicit conditions concerning the generating functions of these sets. This generalizes the earlier results of Nazarov-Perez-Volberg, Łaba-Zhai, and Bond-Volberg.