Categorical properties of the complex numbers

<p>Given the success of categorical approaches to quantum theory, it is interesting to consider why the complex numbers are special from a categorical perspective. We describe natural categorical conditions under which the scalars of a monoidal †-category gain many of the features of the compl...

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Main Author: Vicary, J
Format: Journal article
Language:English
Published: 2011
Subjects:
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author Vicary, J
author_facet Vicary, J
author_sort Vicary, J
collection OXFORD
description <p>Given the success of categorical approaches to quantum theory, it is interesting to consider why the complex numbers are special from a categorical perspective. We describe natural categorical conditions under which the scalars of a monoidal †-category gain many of the features of the complex numbers. Central to our approach are †-<em>limits</em>, certain types of limits which are compatible with the †-functor; we explore their properties and prove an existence theorem for them. Our main theorem is that in a nontrivial monoidal †-category with finite †-limits and simple tensor unit, and in which the self-adjoint scalars satisfy a completeness condition, the scalars are valued in the complex numbers, and scalar involution is exactly complex conjugation.</p>
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spelling oxford-uuid:66da9dc5-afda-41b8-8f0f-168b079257672022-03-26T18:34:28ZCategorical properties of the complex numbersJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:66da9dc5-afda-41b8-8f0f-168b07925767Quantum theory (mathematics)EnglishOxford University Research Archive - Valet2011Vicary, J<p>Given the success of categorical approaches to quantum theory, it is interesting to consider why the complex numbers are special from a categorical perspective. We describe natural categorical conditions under which the scalars of a monoidal †-category gain many of the features of the complex numbers. Central to our approach are †-<em>limits</em>, certain types of limits which are compatible with the †-functor; we explore their properties and prove an existence theorem for them. Our main theorem is that in a nontrivial monoidal †-category with finite †-limits and simple tensor unit, and in which the self-adjoint scalars satisfy a completeness condition, the scalars are valued in the complex numbers, and scalar involution is exactly complex conjugation.</p>
spellingShingle Quantum theory (mathematics)
Vicary, J
Categorical properties of the complex numbers
title Categorical properties of the complex numbers
title_full Categorical properties of the complex numbers
title_fullStr Categorical properties of the complex numbers
title_full_unstemmed Categorical properties of the complex numbers
title_short Categorical properties of the complex numbers
title_sort categorical properties of the complex numbers
topic Quantum theory (mathematics)
work_keys_str_mv AT vicaryj categoricalpropertiesofthecomplexnumbers