Department of Mathematics and Computer Science
Number Theory and Combinatorics Seminar
Fall 2022
For more information, contact Félix Baril Boudreau <>
or Bobby Miraftab <>.

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, and also sent to our mailing list.
                  The next talk:

Sep 26
at noon
in M1040
Dang-Khoa Nguyen
(University of Calgary)  
Height gaps for coefficients of D-finite power series
A power series $f(x_1,\ldots,x_m)\in \mathbb{C}[[x_1,\ldots,x_m]]$ is said to be D-finite if all the partial derivatives of $f$ span a finite dimensional vector space over the field $\mathbb{C}(x_1,\ldots,x_m)$. For the univariate series $f(x)=\sum a_nx^n$, this is equivalent to the condition that the sequence $(a_n)$ is P-recursive meaning a non-trivial linear recurrence relation of the form: $$P_d(n)a_{n+d}+\cdots+P_0(n)a_n=0$$ where the $P_i$'s are polynomials. In this talk, we consider D-finite power series with algebraic coefficients and discuss the growth of the Weil height of these coefficients.

This is from a joint work with Jason Bell and Umberto Zannier in 2019 and a more recent work in June 2022.

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

Sep 12 everyone Organizational meeting and problem session

no seminar on September 19    (University Holiday)

Sep 26 Dang-Khoa Nguyen Height gaps for coefficients of D-finite power series
(University of Calgary)

Oct 3 Debanjana Kundu Title TBA
(University of British Columbia)

no seminar on October 10    (Thanksgiving)

Oct 17 Elchin Hasanalizade Title TBA

Oct 24 Speaker TBA Title TBA

Oct 31 Hugo Chapdelaine Title TBA
via zoom (Université Laval)

no seminar on November 7    (Reading Week)

Nov 14 Julie Desjardins Title TBA
via zoom (University of Toronto)

Nov 21 Solaleh Bolvardizadeh Title TBA

Nov 28 Mathieu Dutour Title TBA
(University of Alberta)

Dec 5 Alexandra Florea Title TBA
via zoom (University of California - Irvine)

Past semesters: Fall F2007 F2008 F2009 F2010 F2011 F2012 F2013 F2014 F2015 F2016 F2017 F2018 F2019 F2020 F2021
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Click here for a PDF file of abstracts of all talks back to 2007 (approx 425K).