Department of Mathematics and Computer Science  
Number Theory and Combinatorics Seminar  
Spring 2023  
For more information,
contact
Félix Baril Boudreau
<felix.barilboudreau@uleth.ca>.
Talks are usually at noon on Monday in room M1040 (Markin Hall). All times are Mountain Time.  
The live access zoom link is available here and on researchseminars.org, and is also sent to our mailing list. 
The next talk:  


Feb 6
at noon via zoom 
Cristhian Garay
(CIMAT Guanajuato, Mexico) 
Generalized valuations and idempotization of schemes
Classical valuation theory has proved to be a valuable tool in number theory, algebraic geometry and singularity theory. For example, one can enrich spectra of rings with new points coming from valuations defined on them and taking values in totally ordered abelian groups. Totally ordered groups are examples of idempotent semirings, and generalized valuations appear when we replace totally ordered abelian groups with more general idempotent semirings. An important example of idempotent semiring is the tropical semifield. As an application of this set of ideas, we show how to associate an idempotent version of the structure sheaf of a scheme, which behaves particularly well with respect to idempotization of closed subschemes. This is a joint work with Félix Baril Boudreau. 
Click on any title for more info, including the abstract. Then
click on it again to hide the info.
When available, click on the mathtube icon to access a videorecording of the talk. 
Date  Speaker  Title  


Jan 9  Youness Lamzouri  A walk on Legendre paths  
(Institut Élie Cartan de Lorraine, France)
PIMS Distinguished Speaker Series 



Jan 16  Neelam Kandhil  On linear independence of Dirichlet Lvalues  
at 9:30am via zoom 
(Institute of Mathematical Sciences, Chennai, India)  


Jan 23  Antonella Perucca  Recent advances in Kummer theory  
via zoom 
at 9:30am (University of Luxembourg)  


Jan 30  Oussama Hamza  Filtrations, arithmetic and explicit examples in an equivariant context  
via zoom  (University of Western Ontario)  


Feb 6  Cristhian Garay  Generalized valuations and idempotization of schemes  
(CIMAT Guanajuato, Mexico)  


Feb 6  Cristhian Garay  An invitation to the algebraic geometry over idempotent semirings  
3:10–4:45pm in B716 
(CIMAT Guanajuato, Mexico) 
Minicourse, Lecture 1 

The minicourse will also be streamed online. To attend (one or both sessions) via zoom, register at:
https://uleth.zoom.us/meeting/register/tJYucuqrz4pE93dDYPcP3Ek7CbrJCFISazV  


Feb 9  Cristhian Garay  An invitation to the algebraic geometry over idempotent semirings  
3:10–4:45pm in B716 
(CIMAT Guanajuato, Mexico) 
Minicourse, Lecture 2 

The minicourse will also be streamed online. To attend (one or both sessions) via zoom, register at:
https://uleth.zoom.us/meeting/register/tJYucuqrz4pE93dDYPcP3Ek7CbrJCFISazV  


Feb 13  Speaker TBA  Title TBA  


Feb 27  Florent Jouve  Title TBA  
via zoom 
at 9:30am (Université de Bordeaux, France)  


Mar 6  John Voight  Title TBA  
via zoom 
at noon (Dartmouth College, USA)  


Mar 13  Renate Scheidler  Title TBA  
(University of Calgary)  


Mar 20  Joshua Males  Title TBA  
(University of Manitoba)  


Mar 27  Douglas Ulmer  Title TBA  
(University of Arizona)  


Apr 3  Harald Andrés Helfgott  Title TBA  
via zoom 
at time tba (University of Göttingen, Germany, and Institut de Mathématiques de Jussieu, France)  

Past semesters:  Fall  F07  F08  F09  F10  F11  F12  F13  F14  F15  F16  F17  F18  F19  F20  F21  F22 
Spring  S08  S09  S10  S12  S13  S14  S15  S16  S17  S18  S19  S20  S21  S22 
Click here for a PDF file of abstracts of all talks back to 2007 (approx 440K). 