Singularities, thresholds, and arithmetic jets/arcs

Various invariants in birational geometry enjoy significant broad topological interest, notably among them the log canonical threshold of a complex hypersurface. In this talk, we'll discuss these invariants and the important Hara-Yoshida conjecture which can be interpreted as a special case of the ordinarity conjecture.  An avenue to study this conjecture comes from the theory of jet and arc spaces. After seeing this potential line attack, we'll discuss an arithmetic version of jet spaces, and introduce their perfectoid arc analogues.

This is joint work with A. Buium. 


Note: This will be a Zoom talk in the sense that the speaker will be attending and delivering the talk via Zoom, however the Zoom will be projected on screens in Seminar Room 1.33. Attendees may choose to view the talk in the Seminar Room or join independently via the Zoom link below.

In person attendance is available in HN 1.33 for up to 52 people.

All attendees will be asked to check in using the CBR Covid-safe Check-In app or sign in on arrival.

To join this seminar via Zoom please click here.

If you would like to join the seminar online and are not currently affiliated with ANU, please contact Martin Helmer at