We define a notion of weak cubical category, abstracted from the structure of n-cubical cospans x : ∧ → X in a category X, where ∧ is the ‘formal cospan’ category. These diagrams form a cubical set with compositions x +i y in all directions, which are computed using pushouts and behave ‘categorically’ in a weak sense, up to suitable comparisons. Actually, we work with a ‘symmetric cubical struc...

in his paper mentioned in the title, which appears in the same issue of this journal, mehdi radjabalipour derives the cyclic decomposition of an algebraic linear transformation. a more general structure theory for linear transformations appears in irving kaplansky's lovely 1954 book on infinite abelian groups. we present a translation of kaplansky's results for abelian groups into the...

This manuscript will be published as Chapter 5 in Wiley’s textbook Mathematical Tools for Physicists, 2nd edition, edited by Michael Grinfeld from the University of Strathclyde. The chapter provides an introduction to the basic concepts of Algebraic Topology with an emphasis on motivation from applications in the physical sciences. It finishes with a brief review of computational work in algebr...

Algebraic topology is at a point of inflection today, and the Spring 2014 Algebraic Topology program at MSRI reflects the excitement of this moment. The introductory workshop, with more than 200 participants, provided careful introductions to the dominant themes leading up to this moment, giving an informative welcome to the many young researchers in the program and attending the conference. Th...