Institute of Information Science Academia Sinica
Topic: Applied Logics Seminar Series(XXXVIII) -- Asser's conjecture and descriptive complexity theory
Speaker: Prof. Tony Tan (Department of Computer Science and Information Engineering, National Taiwan University )
Date: 2018-03-23 (Fri) 15:30 – 17:30
Location: Auditorium 108 at IIS Old Building
Host: Churn-Jung Liau


In 1951, Scholz defined the notion of first-order spectra, and immediately after, in 1955, Asser asked a seemingly innocent question whether first-order spectra are closed under complement. It was rather surprising that in 1970's Jones, Selman and Fagin showed that Asser's question is indeed equivalent to the question NE vs. co-NE. In this talk we will briefly review the connection between Asser's conjecture and descriptive complexity theory. We will also highlight some recent results.