Descent for discrete (co)fibrations

• Author(s): Sobral, Manuela
• Date: 2003
• Persistent ID: http://hdl.handle.net/10316/11440
• Origin: Estudo Geral - Universidade de Coimbra
• Subject(s): Descent data; (e ective) descent morphisms; (co) fibrations; Discrete (co)fi brations; Lax epimorphisms
• Document Type: Preprint
• Language: English

Description

We characterize the (e ective) E-descent morphisms in the category Cat of small categories, when E is the class of discrete fibrations or the one of discrete co fibrations, and prove that every e ective global-descent morphism is an e ective E-descent morphism while its converse fails. The Fields Institute, ATLANTIS 98-00-CAN-0017-00; INTAS 97-31961