Extending multipliers from semigroups

Laca, Marcelo; Raeburn, Iain

doi:10.1090/S0002-9939-1995-1227519-6

Extending multipliers from semigroups
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by Marcelo Laca and Iain Raeburn PDF

Proc. Amer. Math. Soc. 123 (1995), 355-362 Request permission

Abstract:

A multiplier on a normal subsemigroup of a group can be extended to a multiplier on the group. This is used to show that normal cancellative semigroups have the same second cohomology as the group they generate, generalising earlier results of Arveson, Chernoff, and Dinh. The main tool is a dilation theorem for isometric multiplier representations of semigroups.

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