Category Theory Seminars

Category theory seminars are typically held in Ross N638 on Thursday afternoons, from 1:00 to 2:30pm.

Seminars 2017-2018

Tuesday, July 25, 2:00p.m. to 3:00p.m., N638 Ross
Lurdes Sousa, CMUC at the University of Coimbra and Polytechnic Institute of Visen, Portugal
"On algebras with structure adjoint to the unit"
Tuesday, July 25, 3:30p.m. to 4:30p.m., N638 Ross
Leila Yeganeh, Kerman University, Iran

Seminars 2016-2017

Friday, May 12, 1:20p.m. to 2:30p.m., N638 Ross
Elza Ivanova-Dimova, Sofia University
"Vietoris-type Topologies and Hyperspaces"
Friday, May 12, 2:30p.m. to 3:30p.m., N638 Ross
Georgi Dimov, Sofia University
"A Generalization of the Stone Duality Theorem"

Seminars 2015-2016

December 17, 2015
Lili Shen, York University
A General Representation Theorem for Concept Lattices
Thursday, December 10, 2015
Nasir Sohail, Wilfried Laurier University
Epimorphisms and Amalgamation for Ordered Algebras

I shall first give examples to show that the (strong) amalgamation of algrebras (in particular monoids) may be severely affected if an order is introduced on top of the algebraic structure. I shall then show that epimorphisms in a category of ordered monoids, nonetheless, coincide with those of the 'underlying category' of monoids. I shall then discuss a possibility of generalizing this result to general algebras.
This talk will be based on the following work.
[1] Sohail Nasir: Epimorphisms, dominions and amalgamation in pomonoids. Semigroup Forum 90 (3), 800-809 (2015)
[2] Valdis Laan and Sohail Nasir: On mono- and epimorphisms in varieties of ordered algebras. Communications in Algebra 43: 2802-2819 (2015)

November 15, 2015
Walter Tholen, York University
What is Monoidal Topology, and What Can it Do?
November 12, 2015
Walter Tholen, York University
Towards Monad-quantaloid-enriched Topological Structures
October 29, 2015
Hongliang Lai, Sichuan University
Directed Completeness of DQ-categories: Flat Weights and Cauchy Weights
October 22, 2015
Hongliang Lai, Sichuan University
The Cartesian closed category of liminf-complete Q-categories
October 15, 2015
Hongliang Lai, Sichuan University
The The Monoidal Closed Category of Liminf-complet Q-categories