When:
Monday, November 3, 2025
4:00 PM - 5:00 PM CT
Where: Lunt Hall, 104, 2033 Sheridan Road, Evanston, IL 60208 map it
Audience: Faculty/Staff - Post Docs/Docs - Graduate Students
Contact:
Noah Riggenbach
noah.riggenbach@northwestern.edu
Group: Department of Mathematics: Topology Seminar
Category: Lectures & Meetings
Title: Spherical delta-rings
Abstract: The notion of a delta-ring is central to the site-theoretic definition of prismatic cohomology. In this talk, I’ll introduce a variant for E_infty rings which enjoys two nice basic features: pi_0 of a connective spherical delta-ring is an ordinary delta-ring and the cofree spherical delta ring on a discrete perfect Fp-algebra recovers the spherical Witt vectors of Lurie and Burklund-Schlank-Yuan. This is joint work in progress with Thomas Nikolaus.