After the outbreak of the coronavirus pandemic, a few scientific communities faced cancellations of conferences, seminars, and research visits. Motivated by the need to establish new communication channels, a series of seminars called One World Seminars was initiated, as an attempt to keep the communities together. The pioneer of this project was One World Probability Seminar that inspired several other One World projects (among which, you might know the One World Combinatorics on Words Seminar).

This is a new series of online research seminars on topics related to Formal Languages and Automata Theory: One FLAT World Seminar (yes, we know, we broke a pattern here: we should have named it “One World FLAT Seminars”, but this name is funnier).

The main goal of this project is to keep the community working in our area alive and updated, by bringing together researchers from all over the world in a virtual, accessible, and inclusive environment. We believe that recently our community is quite fragmented, so having a common platform to share old and recent results on the one hand would help established researchers working on similar topics to find collaborators and fresh ideas and, on the other hand, young people, new in the area, would have a clear vision of what is going on in this branch of theoretical computer science.

The talks will be accessible via Zoom and will run, at least at the beginning, on a monthly basis.

Speakers Wanted!

If you would like to volunteer to be the speaker at one of our sessions in 2026, please feel free to drop us an email with the details of your talk.

Upcoming talks

• Subregular Expressions and Their Expressive Power

  Speaker: Matthias Wendland

  September 23, 2026 at 13:00 UTC (your local time: )

  

  

  Regular expressions are classically built using concatenation, union, and Kleene star. Since regular languages are closed under many additional operations, these operations can also be incorporated into expressions without increasing expressive power. This talk investigates how the expressive capabilities change when alternative sets of operations are used instead of the classical ones. We consider several variants of subregular expressions, obtained either by omitting standard operations or by replacing them with operations such as complementation or intersection. The talk presents an overview of recent results concerning the expressive power, structural properties, and closure behavior of the resulting language families. Particular emphasis... [Read More]