Lehmer’s Conjecture for Hermitian Matrices over the Eisenstein and Gaussian Integers

My third paper on the Mahler measure problem has been accepted by the Electronic Journal of Combinatorics, and is available here freely under the E-JC’s open access policy. This is joint work with Gary Greaves, and completes the proof of Lehmer’s conjecture for matrices with entries from rings of integers of quadratic extensions: a project …

Continue reading ‘Lehmer’s Conjecture for Hermitian Matrices over the Eisenstein and Gaussian Integers’ »

‘Introduction to Graph Theory’ Lecture Materials

I have now completed a series of introductory lectures on Graph Theory, for 3rd/4th year students at the University of Bristol. A set of written notes plus (less usefully) my slides are mirrored here. One student declared this to be “[the] most interesting course I have taken at Bristol Uni”, so take a look to …

Continue reading ‘‘Introduction to Graph Theory’ Lecture Materials’ »

JMM 2013 Highlights

Earlier this month I attended the 2013 Joint Mathematics Meetings, trading freezing Britain for sunny San Diego! This was the 119th annual meeting of the American Mathematical Society, the 96th of the Mathematical Association of America, my third trip to the US for a JMM, and the first at which I’ve given a talk. There …

Continue reading ‘JMM 2013 Highlights’ »

Undergraduate Projects at the University of Bristol

I’m offering a couple of possible projects for third-year students at Bristol (i.e., for MATH32001 or MATH32200 depending on amount of time) in the upcoming academic year (2012/13). Other topics in areas such as spectral graph theory or computational number theory could also be possibilities; students are welcome to get in touch (via my magdt@bristol …

Continue reading ‘Undergraduate Projects at the University of Bristol’ »

Updated: Lehmer’s conjecture for matrices over the ring of integers of some imaginary quadratic fields

Just a brief note that my second paper on my thesis topic has been accepted by the Journal of Number Theory. The full citation is: Graeme Taylor, Lehmer’s conjecture for matrices over the ring of integers of some imaginary quadratic fields, Journal of Number Theory, Volume 132, Issue 4, April 2012, Pages 590-607, ISSN 0022-314X, …

Continue reading ‘Updated: Lehmer’s conjecture for matrices over the ring of integers of some imaginary quadratic fields’ »

New records for integral multiples of points

I’ve been trying to extend the results of the work described in this post, and following a suggestion of Noam Elkies have changed my search strategy from points corresponding to simple EDS triples to those given by (A,u,c) parametrisations as described here. Experimenting with these revealed some serious deficiencies with the height function in SAGE, …

Continue reading ‘New records for integral multiples of points’ »

Nontorsion Points of Low Height on Elliptic Curves over Quadratic Fields

I have uploaded a preprint of some recent efforts to the arXiv. In a break from my cyclotomic matrix work, this revisits a project I first became interested in over four years ago: the search for points with small height on elliptic curves over number fields, through the use of elliptic divisibility sequences. There used …

Continue reading ‘Nontorsion Points of Low Height on Elliptic Curves over Quadratic Fields’ »

Cyclotomic Matrices and Graphs: Waterloo

I gave the Number Theory Seminar at the Department of Pure Mathematics, University of Waterloo on Thursday, September 8th. My slides are available in presentation or handout form (except the latter is missing the interlacing demo which didn’t render into individual slides correctly). I used this talk as an opportunity to present some results that …

Continue reading ‘Cyclotomic Matrices and Graphs: Waterloo’ »