Sacks Prize for Andreas Lietz
Congratulations to Dr. Andreas Lietz! The Association for Symbolic Logic (ASL) has awarded him the Sacks Prize for the most outstanding doctoral dissertation in mathematical logic in 2023.
Andreas Lietz is currently a postdoc at TU Wien. He received his PhD in 2023 under the guidance of Prof. Dr. Ralf Schindler at Mathematics Münster.
About his dissertation "A journey guided by the stars"
His dissertation is titled "Forcing ‘NSω_1 is ω1-dense‘ from large cardinals – a journey guided by the stars". He solved a long-standing problem as to whether it was possible to force over a ZFC model the assertion that the non-stationary ideal over omega_1 could be omega_1-dense. This was a prominent assertion in set theory and had been used by Woodin and others in the so-called core-model induction. It is equiconsistent with the assertion that there exist infinitely many Woodin cardinals, and hence also with the Axiom of Determinacy. Woodin had obtained this assertion by forcing over models of determinacy. Nevertheless, it had been an open question for some 30 years as to whether the assertion could be forced, in particular, by using semi-proper forcing, over a model of ZFC.
Andreas Lietz answered this question affirmatively by demonstrating that starting from a model with a cardinal kappa that is an inaccessible limit of <-kappa-supercompacts, one could obtain this property in the generic extension by a stationary set-preserving forcing. Moreover using the novel techniques he invented, Lietz went on to also isolate a whole variety of axioms that are variants of MM, Martin’s Maximum.
About the Sacks Prize
The Sacks Prize is awarded annually for the most outstanding doctoral dissertation in mathematical logic; it was established to honor the late Professor Gerald Sacks of MIT and Harvard for his unique contribution to mathematical logic, particularly as an adviser to a large number of excellent PhD researchers. The Prize became an ASL Prize in 1999; the Fund on which the Prize is based is now administered by the ASL and the selection of the recipient is made by the ASL Committee on Prizes and Awards. The Sacks Prize consists of a cash award plus five years free membership in the ASL.
Links:
Association for Symbolic Logic (ASL): Sacks Prize Recipients
https://andreas-lietz.github.io/resources/PDFs/AJourneyGuidedByTheStars.pdf - Doctoral thesis of Andreas Lietz