Call For Posters

University of Michigan

If you are a graduate student and would like to participate in the poster session, please send by e-mail your title, affiliation and full abstract (approximately 100-150 words) NO LATER THAN MAY 21 to:

William A. Massey

E-mail: will@research.bell-labs.com

Phone: 908-582-3225

Note: Please send your title and abstract as a regular TEXTFILE. If your abstract includes mathematical formulas, please write them as TEX (see the sample below). The poster session will be held 4:45-6:45 pm Wednesday, June 23 at the University of Michigan. Materials such as poster boards, push pins, tape, etc. will be PROVIDED there. You only need to bring the mathematics (exposition, formulas, and graphs). We look forward to seeing you in Ann Arbor!!

- Poster boards will be 30" by 40".
- You will be explaining your posters to the other attendees of the conference.
- Make panels (8 1/2" by 11" sheets of paper preferably) that can be tacked up onto the board provided. This will make it easier to set-up and transport the poster.
- Your panels will consist of:
- Exposition (things like an overview, definitions, statement of goals, statement of results, etc.).
- Formulas (SLITEX if available, is a nice way to do them, but in general just make sure that the fontsize for your exposition and formulas in the poster panels is at least twice as big as for a paper you would publish).
- Graphs (if your talk lends itself to that).
- Pictures (diagrams and illustrations are always a plus).

- Your poster must be prepared and ready to go by 5:00 pm on June 25. Be sure to check with the conference personnel at the checkin area upon arrival in order to make the necessary arrangements.

A POLYOMINO TILING PROBLEM OF THURSTON AND ITS CONFIGURATIONAL ENTROPY

Terry Gauss Newton

Department of Mathematics

University of Hilbert Space

xyz@hilbert.space.edu

We prove a conjecture of Thurston on tiling a certain triangular region $T_{3N+1}$ of the hexagonal lattice with three-in-line (``tribone'') tiles. It asserts that for all packings of $T_{3N+1}$ with tribones leaving exactly one uncovered cell, the uncovered cell must be the central cell. Furthermore, there are exactly $2^{N}$ such packings. This exact counting result is analogous to closed formulae for the number of allowable configurations in certain exactly solved models in statistical mechanics, and implies that the configurational entropy (per site) of tiling $T_{3N+1}$ with tribones with one defect tends to 0 as $N \rightarrow \infty$.

Last modified Mon 19 Apr 1999 14:26 EDT

Bob MegginsonDepartment of Mathematics

University of Michigan

meggin@math.lsa.umich.edu