The Fourier transform of functions of the greatest common divisor.
For a finite commutative ring and a positive integer , we construct an iteration digraph whose vertex set is and for which there is a directed edge from to if . Let , where and is a finite commutative local ring for . Let be a subset of (it is possible that is the empty set ). We define the fundamental constituents of induced by the vertices which are of the form if , otherwise where U denotes the unit group of and D denotes the zero-divisor set of . We investigate...
It is known that with a non-unit Pisot substitution one can associate certain fractal tiles, so-called Rauzy fractals. In our setting, these fractals are subsets of a certain open subring of the adèle ring of the associated Pisot number field. We present several approaches on how to define Rauzy fractals and discuss the relations between them. In particular, we consider Rauzy fractals as the natural geometric objects of certain numeration systems, in terms of the dual of the one-dimensional realization...
The Golomb space is the set of positive integers endowed with the topology generated by the base consisting of arithmetic progressions with coprime . We prove that the Golomb space is topologically rigid in the sense that its homeomorphism group is trivial. This resolves a problem posed by T. Banakh at Mathoverflow in 2017.