Uncountable orthogonality is a closure property

Warning

This publication doesn't include Faculty of Arts. It includes Faculty of Science. Official publication website can be found on muni.cz.

Authors	HÉBERT M. ROSICKÝ J.
Year of publication	2001
Type	Article in Periodical
Magazine / Source	Buletin of the London Mathematical Society
MU Faculty or unit	Faculty of Science
Citation	HÉBERT, M. and J. ROSICKÝ. Uncountable orthogonality is a closure property. Buletin of the London Mathematical Society. London: London Mathematical Society, 2001, vol. 33, No 2, p. 685-688. ISSN 0024-6093.
Field	General mathematics
Keywords	locally presentable category; orthogonality class
Description	It is shown that, for k uncountable, k-orthogonality classes in locally k-presentable categories coincide with full subcategories that are closed under limits and k-directed colimits. This comes as a surprise, since the statement is known to be false for k countable.
Related projects:	Categorical methods of the theory of structures and computer science Mathematical structures of algebra and geometry