- Series
- Combinatorics Seminar
- Time
- Friday, March 16, 2012 - 3:05pm for 1 hour (actually 50 minutes)
- Location
- Skiles 005
- Speaker
- Mihai Ciucu – Mathematics, Indiana University, Bloomington, IN
- Organizer
- Prasad Tetali
The correlation of gaps in dimer systems was introduced in 1963 by
Fisher and Stephenson, who looked at the interaction of two monomers
generated by the rigid exclusion of dimers on the closely packed square
lattice. In previous work we considered the analogous problem on the
hexagonal lattice, and we extended the set-up to include the correlation of
any finite number of monomer clusters. For fairly general classes of monomer
clusters we proved that the asymptotics of their correlation is given, for
large separations between the clusters, by a multiplicative version of
Coulomb's law for 2D electrostatics. However, our previous results required
that the monomer clusters consist (with possibly one exception) of an even
number of monomers. In this talk we determine the asymptotics of general
defect clusters along a lattice diagonal in the square lattice (involving an
arbitrary, even or odd number of monomers), and find that it is given by the
same Coulomb law. Of special interest is that one obtains a conceptual
interpretation for the multiplicative constant, as the product of the
correlations of the individual clusters. In addition, we present several
applications of the explicit correlation formulas that we obtain.