Department of

September 2018 October 2018November 2018Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We ThFrSa 1 1 2 3 4 5 6 1 2 3 2 3 4 5 6 7 8 7 8 9 10 11 12 13 4 5 6 7 8 9 10 9 10 11 12 13 14 15 14 15 16 17 18 19 20 11 12 13 14 151617 16 17 18 19 20 21 22 21 22 23 24 25 26 27 18 19 20 21 22 23 24 23 24 25 26 27 28 29 28 29 30 31 25 26 27 28 29 30 30

Tuesday, October 9, 2018

**Abstract:** It is generally accepted that the structure of the $E(n)$-local homotopy theory, where $E(n)$ is the p-local Johnson-Wilson spectrum at height $n$, becomes increasingly algebraic when $p$ is large with respect to $n$. To give two examples of this phenomena, when the prime is large, the $E(n)$-based Adams spectral sequence collapses on the second page for degree reasons, giving an algebraic description of the homotopy of the $E(n)$-local sphere. Moreover, it is a result of Hovey and Sadofsky that the only invertible spectra in this range are the spheres, showing that the $E(n)$-local Hopkins' Picard group is isomorphic to the integers at large primes, in stark contrast to what happens when $p$ is small. In this talk, we show that when $p > n^2+n+1$, the homotopy category of $E(n)$-local spectra is equivalent to the homotopy category of differential $E(n)_*E(n)$-comodules, giving a precise sense in which chromatic homotopy is "algebraic" at large primes. This extends the work of Bousfield at $n = 1$ to all heights, and affirms a conjecture of Franke.