Proper Equivariant Stable Homotopy Theory Dieter Degrijse Markus Hausmann Wolfgang L¨uck Irakli Patchkoria Stefan Schwede Author address: Keylane, Copenhagen, Denmark Email address:
[email protected] Department of Mathematical Sciences, Københavns Universitet, Denmark Email address:
[email protected] Mathematisches Institut, Universitat¨ Bonn, Germany Email address:
[email protected] Department of Mathematics, University of Aberdeen, UK Email address:
[email protected] Mathematisches Institut, Universitat¨ Bonn, Germany Email address:
[email protected] Contents Introduction 1 Chapter 1. Equivariant spectra 5 1.1. Orthogonal G-spectra 5 1.2. The stable model structure 12 1.3. The G-equivariant stable homotopy category 31 1.4. Change of groups 37 Chapter 2. Equivariant homotopy groups 59 2.1. G-equivariant homotopy groups 59 2.2. Equivariant homotopy groups as Mackey functors 69 2.3. Rational proper stable homotopy theory 75 Chapter 3. Proper equivariant cohomology theories 81 3.1. Excisive functors from G-spectra 81 3.2. Proper cohomology theories from G-spectra 102 3.3. Global versus proper stable homotopy types 110 3.4. Equivariant K-theory 118 Bibliography 133 Index 137 iii Abstract This monograph introduces a framework for genuine proper equivariant stable homotopy theory for Lie groups. The adjective `proper' alludes to the feature that equivalences are tested on compact subgroups, and that the objects are built from equivariant cells with compact isotropy groups; the adjective `genuine' indicates that the theory comes with appropriate transfers and Wirthm¨ullerisomorphisms, and the resulting equivariant cohomology theories support the analog of an RO(G)- grading. Our model for genuine proper G-equivariant stable homotopy theory is the category of orthogonal G-spectra; the equivalences are those morphisms that induce isomorphisms of equivariant stable homotopy groups for all compact subgroups of G.