6 papers
Multipliers and Disjointness from Mixing
Sohail Farhangi, Joel Moreira, Rigoberto Zelada
In 2005, Parreau proved that if a measure preserving system is not strongly mixing then it contains a non-trivial factor that is disjoint from every strongly mixing system. Taking…
Asymptotic dynamics on amenable groups and van der Corput sets
Sohail Farhangi, Robin Tucker-Drob
We answer a question of Bergelson and Lesigne by showing that the notion of van der Corput set does not depend on the Følner sequence used to define it. This result has been disco…
The Theory of Normality for Dynamically Generated Cantor Series Expansions
Sohail Farhangi, Bill Mance
The theory of normality for base expansions of real numbers in is rich and well developed. Similar theories have been developed for many other numeration systems, such…
On the Jacobs-de Leeuw-Glicksberg decomposition for representations of semigroups
Micky Barthmann, Sohail Farhangi, Yulia Kuznetsova
We develop a systematic study of the Jacobs-de Leeuw-Glicksberg decomposition for JdLG-admissible semigroup representations on Banach spaces, with emphasis on its structural, ergod…
Undecidability in the Ramsey theory of polynomial equations and Hilbert's tenth problem
Sohail Farhangi, Steve Jackson, Bill Mance
We show that several sets of interest arising from the study of partition regularity and density Ramsey theory of polynomial equations over integral domains are undecidable. In par…
Uniform vector-valued pointwise ergodic theorems for operators
Micky Barthmann, Sohail Farhangi
We prove a uniform vector-valued Wiener-Wintner Theorem for a class of operators that includes compositions of ergodic Koopman operators with contractive multiplication operators.…