Combinatorics and Computing Weekly Seminar
Proof of a Conjecture of Cavenagh, Hamalainen, Lefevre, and Stones
Proof of a Conjecture of Cavenagh, Hamalainen, Lefevre, and Stones
Amin Bahmanian, Illinois State University
23 OCT 2024
14:00 - 15:00
An $r imes r$ {it $lambda$-Latin square} ({it rectangle}, respectively) is an $r imes r$ array in which each cell contains a multiset of $lambda$ elements from the set ${1,dots,r}$ of symbols such that each symbol occurs exactly $lambda$ times (at most $lambda$ times, respectively) in each row and column. Cavenagh, Hämäläinen, Lefevre, and Stones asked for conditions that ensure a simple λ-Latin rectangle can be extended to a simple λ-Latin square. We solve this problem in a more general setting by allowing the number of occurrences of each symbol to be prescribed. Cavenagh et al. also conjectured that for each r,λ there exists some n(r,λ) such that for any n ≥ n(r,k), every simple partial λ-Latin square of order r embeds in a simple λ-Latin square of order n. We confirm this conjecture.
Zoom room information:
https://us06web.zoom.us/j/85237260136?pwd=MFSZoKdmRXAjfaSaBzbf19lTaaKglf.1
Meeting ID: 852 3726 0136
Passcode: 362880
Venue: Niavaran, Lecture Hall 1