U. Haifa Topology & Geometry seminar: Sunday, Apr. 10, 2022. Speaker: Niles Johnson (Ohio State University). Title: “Graded Picard categories and the 2-type of the sphere”.

Time: 17:00 (Israel Time)

Location: On Zoom





Abstract: The Stable Homotopy Hypothesis connects symmetric monoidal
algebra and stable homotopy theory.  In a classical special case, the
the tensor product of graded abelian groups leads to a model for the 1-dimensional stable homotopy of the sphere spectrum.  In that case, the nontrivial sign rule for commuting elements corresponds to nontriviality in the first Postnikov invariant of the sphere. This talk describes a generalization to graded Picard categories, modeling the 2-dimensional stable homotopy of the sphere.  The possible sign rules for this case reduce to certain elementary permutations.

The work we present is joint with N. Gurski and A.M. Osorno.



Meeting ID: 849 8759 1026

Future speakers:

Surojit Ghosh (IIT Roorkee) – April 24th

Dimitri Ara (Marseilles) – May 1st

Sourav Das (Haifa) – May 8th

Viktoriya Ozornova (Bonn) – May 15th

Andrew Salch (Wayne State) – May 22nd

Markus Upmeier (Aberdeen) – May 29th

Denis-Charles Cisinski (Regensburg) – June 5th.