homotopy – Konrad Voelkel's Blog

I just found, purely by luck, a recent blog about chromatic homotopy theory and various other mathematical topics. It’s a group blog called Chromotopy, written by Brendan Pawlowski, Eric Peterson, Erik Davis and Stephen Checkoway. They started February 2010.
The first posts (from Feb 2010 to June 2010):

Grand opening
Schreier theory
Jordan type of a modular representation
Bundles for [...]

Chapter 2.1. Homotopy theory of simplicial sheaves: The simplicial model category structure. Discussion of 1.2, 1.3, 1.4, 1.5, 1.6, 1.8, 1.9, 1.10.

Background needed to understand Morel-Voevodsky’s paper “A¹-homotopy theory”. I explain simplicial sets, topoi, monoidal categories, enriched categories and simplicial model categories.

Here is the second part of my walk-through to Morel-Voevodskys A¹-homotopy theory. I give a proof of Lemma 1.1 on page 48.