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Infinite-dimensional representations of 2-groups /

"A '2-group' is a category equipped with a multiplication satisfying laws like those of a group. Just as groups have representations on vector spaces, 2-groups have representations on '2-vector spaces', which are categories analogous to vector spaces. Unfortunately, Lie 2-gr...

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Detalles Bibliográficos
Clasificación:Libro Electrónico
Otros Autores: Baez, John C., 1961-
Formato: Electrónico eBook
Idioma:Inglés
Publicado: Providence, R.I. : American Mathematical Society, ©2012.
Colección:Memoirs of the American Mathematical Society ; no. 1032.
Temas:
Acceso en línea:Texto completo
Descripción
Sumario:"A '2-group' is a category equipped with a multiplication satisfying laws like those of a group. Just as groups have representations on vector spaces, 2-groups have representations on '2-vector spaces', which are categories analogous to vector spaces. Unfortunately, Lie 2-groups typically have few representations on the finite-dimensional 2-vector spaces introduced by Kapranov and Voevodsky. For this reason, Crane, Sheppeard and Yetter introduced certain infinite-dimensional 2-vector spaces called 'measurable categories' (since they are closely related to measurable fields of Hilbert spaces), and used these to study infinite-dimensional representations of certain Lie 2-groups. Here we continue this work. We begin with a detailed study of measurable categories. Then we give a geometrical description of the measurable representations, intertwiners and 2-intertwiners for any skeletal measurable 2-group. We study tensor products and direct sums for representations, and various concepts of subrepresentation. We describe direct sums of intertwiners, and sub-intertwiners--features not seen in ordinary group representation theory. We study irreducible and indecomposable representations and intertwiners. We also study 'irretractable' representations--another feature not seen in ordinary group representation theory. Finally, we argue that measurable categories equipped with some extra structure deserve to be considered 'separable 2-Hilbert spaces', and compare this idea to a tentative definition of 2-Hilbert spaces as representation categories of commutative von Neumann algebras."
Notas:"September 2012, volume 219, number 1032 (end of volume)."
Descripción Física:1 online resource (v, 120 pages) : illustrations
Bibliografía:Includes bibliographical references (pages 117-120).
ISBN:9780821891162
0821891162
ISSN:0065-9266 ;