The Logic seminar generally meets on Fridays, at Caltech or UCLA. Contact Alexander Kechris or Andrew Marks if you wish to give a talk.

**THE SEMINAR MEETS ONLINE, 2:00 to 2:50pm California time, AT https://ucla.zoom.us/j/91552943846?pwd=cWI2ai9ZRlRjQ2NYeGg1T056Sis2UT09. PLEASE MUTE YOUR MICROPHONE EXCEPT WHEN SPEAKING.**

Schedule of talks, going back to Fall
2021, in ** reverse chronological order**:

Sunday Feb 12 2023 | ||||

09:00-13:00 (Very Informal Gathering of Logicians) | This is the 21st in a series of biennial logic meetings at UCLA. This event celebrates Tony Martin's 80th birthday. For a schedule of the talks visit www.logic.ucla.edu | |||

Saturday Feb 11 2023 | ||||

09:00-21:00 (Very Informal Gathering of Logicians) | This is the 21st in a series of biennial logic meetings at UCLA. This event celebrates Tony Martin's 80th birthday. For a schedule of the talks visit www.logic.ucla.edu | |||

Friday Feb 10 2023 | ||||

14:30-19:00 (Very Informal Gathering of Logicians) | This is the 21st in a series of biennial logic meetings at UCLA. This event celebrates Tony Martin's 80th birthday. For a schedule of the talks visit www.logic.ucla.edu | |||

Friday Dec 17 2021 | ||||

14:00-14:50 (https://ucla.zoom.us/j/91552943846?pwd=cWI2ai9ZRlRjQ2NYeGg1T056Sis2UT09) | Andy Zucker (UCSD) | Dynamics and Ramsey theory on countable groups and structures | ||

Abstract. In topological dynamics, one considers the continuous
actions of a topological group on a compact space. We will be most
interested in minimal actions, those for which every orbit is dense,
and Polish groups, groups whose underlying topology is separable and
completely metrizable. For countable discrete groups, we show in a
precise sense that minimal actions can be wildly complicated. By
contrast, for automorphism groups of countable structures, the work of
Kechris, Pestov, and Todorcevic establishes a connection between
groups whose minimal actions are simple and theorems in finite Ramsey
theory. We show that this is in fact the only reason an automorphism
group can have well-behaved minimal actions. With this precise
correspondence in mind, we then consider possible dynamical
formulations of infinite Ramsey theorems. |