Topology Day

Topology Day will include a short series of lectures by special guests, held on March 14, 2017, at the University of Colorado Boulder by the Department of Mathematics.


Please fill out the following Google Form if you plan on attending:           Click Here!


Mark Behrens 12-1pm MATH 350 (Kempner Colloquium)
Mark Behrens 3-4pm MATH 350 (Topology Seminar)
Xiang Tang 4-5pm MATH 350 (Topology Seminar)
Dinner 6:30 pm Location: Boulder Dushanbe Teahouse
See below for details.

Special Lectures:

  • Speaker: Mark Behrens (University of Notre Dame)
  • Title: Detectors in Homotopy Theory
  • Abstract: In physics, the detection of certain particles has required working at increasingly high energy. These accelerator experiments have required increasingly elaborate detectors and data analysis to reconstruct events from the production of dozens, sometimes hundreds of resulting particles. I will use this analogy to discuss the increasingly elaborate "detectors" used in homotopy theory to probe the stable homotopy groups of spheres in increasingly large dimensions. These "detectors" are versions of the Adams spectral sequence. To maximize the accessibility of this talk, I will avoid using the language of spectral sequences.
  • Speaker: Mark Behrens (University of Notre Dame)
  • Title: A Generalization of Quillen-Sullivan Rational Homotopy Theory
  • Abstract: Quillen-Sullivan theory encodes a rational homotopy type in either a differential graded rational Lie algebra, or a differential graded rational commutative algebra. The first encodes the rational homotopy groups, with its Whitehead products, and the second encodes the rational cohomology groups, with its cup products. I will describe a generalization of this theory, joint with Charles Rezk, where "rational homotopy theory" is replaced with "unstable v_n-periodic homotopy theory".
  • Speaker: Xiang Tang (Washington University at St. Louis)
  • Title: A Leray-Hirsch Principle for Gerbes on Orbifolds
  • Abstract: A G-gerbe is a principal BG bundle, where BG is the classifying space of G. In this talk, we will explain what they are, and introduce a Leray-Hirsch principle to study the geometry of G-gerbes on orbifolds. The key ingredient in our development is the Mackey machine for the restriction of a representation. We will aim to make the talk accessible to graduate students.


There will be a dinner held at the Boulder Dushanbe Teahouse at 6:30pm, after the talks. (A reservation for all those that have told one of the organizers that they are coming has been made.) Click here for a map. The address is: 1770 13th St, Boulder.

Organising Committee

Topology Day is supported by the National Science Foundation and the University of Colorado Boulder.