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Monday, January 22, 2018

**Abstract:** Infinite loop spaces arise as the spaces underlying connective spectra. The construction and analysis of such spaces has been an important part of homotopy theory. In this talk I will introduce Segal's infinite loop space machine, a device used to construct infinite loop spaces from algebraic data. Using this machine, I will prove a theorem of Barratt-Priddy-Quillen. Finally, I will indicate how these ideas are being put to use in motivic homotopy theory.