Tuesday, April 24, 2012, 1:55–2:45 in Little 305
Aziza Jefferson (UF)
Avoiding 3-term arithmetic progressions
Tuesday, April 17, 2012, 1:55–2:45 in Little 305
Neil White (UF)
Coxeter groups
Tuesday, April 10, 2012, 1:55–2:45 in Little 305
Cheyne Homberger (UF)
Expected patterns in permutation classes
Tuesday, April 3, 2012, 1:55–2:45 in Little 305
Miklós Bóna (UF)
Tuesday, March 27, 2012, 1:55–2:45 in Little 305
Andrew Vince (UF)
Binary Sequences and Fractals
Tuesday, March 20, 2012, 1:55–2:45 in Little 305
Robert Brignall (The Open University)
Indecomposable graphs and the Reconstruction Conjecture
Tuesday, January 24, 2012, 1:55–2:45 in Little 305
Miklós Bóna (UF)
The absence of a permutation pattern and the number of occurrences of another one
Abstract: we will survey some results (without proofs) from three years ago, then show the proof of a suprising new result. Open problems will be discussed.
Tuesday, November 22, 2011, 4:05–4:55 in Little 368
Michael Albert (University of Dunedin)
Tuesday, November 8, 2011, 4:05–4:55 in Little 368
Andrew Vince
The Eigen-Ellipse
Tuesday, November 1, 2011, 4:05–4:55 in Little 368
Nick Sharpe (UF)
Generalizing the Classical Marriage Lemma, Part 2 of 2
Tuesday, October 25, 2011, 4:05–4:55 in Little 368
Nick Sharpe (UF)
Generalizing the Classical Marriage Lemma, Part 1 of 2
Let n be a positive integer. Suppose there is a set of n boys, each of whom knows at least 1 of a set of n girls, in such a way that any subset of k boys knows at least k girls, for k=1,2,...,n. Then "The Classical Marriage Lemma" (which may also go by other names) says that one can hold a mass wedding in which each boy marries a girl whom he knows.
In my study of Ergodic Theory, I have encountered a generalization of the above, which I plan to talk about:
Suppose A and B are finite sets with p() and q() probability measures on A and B respectively, and that to every element a in A we associate a subset "phi(a)" of B, in such a way that for every subset S of A, p(S) <= q(phi(S)) holds. [Such a phi is called a "society from A to B".] Then there exists another society "nu" from A to B such that for all a in A: nu(a) is a subset of phi(a) [ "nu refines phi" ], AND such that
#{b in B | there exist distinct a1, a2 in A such that b lies in nu(a1) and nu(a2)} < #A .
Tuesday, October 11, 2011, 4:05–4:55 in Little 368
Jindrich Zapletal (UF)
Ramsey theory: a set theorist's view
Monday, October 3, 3:00–3:55 in Little 368
Péter Komjáth (Eötvös Loránd University)
Tuesday, September 6, 2011, 4:05–4:55 in Little 368
Neil White (UF)
Planar configurations
Tuesday, February 8, 2010, 11:45–12:35 in Little 305
Miklós Bóna (UF)
Non-overlapping permutations
Wednesday January 19, 2010, 1:55–2:45 in Little 368
Qing Xiang (University of Delaware)
Cyclotomic constructions of strongly regular graphs and difference sets
Tuesday November 23, 2010, 4:05
Duc Huynh (UF)
Sign-balanced and maj-balanced posets
Thursday November 18, 2010, 4:05
Daniel Gray (UF)
Combinatorial properties of two Fibonacci lattices
Tuesday November 9, 2010, 4:05
Cuong Ngo (UF)
d-Regular set partitions and rook placements
Tuesday November 2, 2010, 4:05
Larie Ward (UF)
Completions of Latin squares
Thursday October 21, 2010, 4:05
Steve Linton (University of St Andrews)
Monotone sequences and coin sliding games
Tuesday October 5, 2010, 4:05
Neil White (UF)
Signed Permutations, plus a gentle introduction to Coxeter Groups
Tuesday September 28, 2010, 4:05
Aziza Jefferson (UF)
Stirling polynomials
Tuesday September 21, 2010, 4:05
Miklós Bóna (UF)
Combinatorics of Genome Rearrangements
Tuesday September 7, 2010, 4:05
Andrew Vince (UF)
A Contractive Metric on a Finite Set