Monday 11 September 2023, 15:00-16:00, Carslaw 535 Speaker: Johannes Schleischitz (Middle East Technical University) Title: Sum and product sets of classes of sets relevant in Diophantine approximation Abstract: Liouville numbers are real numbers that admit very good approximation by rationals. Paul Erdos proved that every real number can be written as the sum (and product) of two Liouville numbers. We extend this result in several directions, in particular considering sum sets of classes of numbers with prescribed or bounded irrationality exponent (the case of infinite exponent recovers Erdos result). This will also admit conclusions on metrical properties of Cartesian products of these sets.