Talk 3: Interlude: Spectra
Jakob Burgi (Universität Heidelberg)

Following [11, Section 1] Explain the motivation behind the construction of spectra. (It might be helpful to explain the analogy of fibers /cofibres with the analogous notion in abelian categories). Mention in particular, in what sense objects represent cohomology theories. This talk will serve as a motivation for the general notion of stable ∞-categories.