464 research outputs found
Combinatorics of r-Dyck paths, r-Parking functions, and the r-Tamari lattices
This paper's aim is to present recent combinatorial considerations on r-Dyck
paths, r-Parking functions, and the r-Tamari lattices. Giving a better
understanding of the combinatorics of these objects has become important in
view of their (conjectural) role in the description of the graded character of
the Sn-modules of bivariate and trivariate diagonal coinvariant spaces for the
symmetric group.Comment: 36 pages, 12 figure
The cyclic sieving phenomenon: a survey
The cyclic sieving phenomenon was defined by Reiner, Stanton, and White in a
2004 paper. Let X be a finite set, C be a finite cyclic group acting on X, and
f(q) be a polynomial in q with nonnegative integer coefficients. Then the
triple (X,C,f(q)) exhibits the cyclic sieving phenomenon if, for all g in C, we
have # X^g = f(w) where # denotes cardinality, X^g is the fixed point set of g,
and w is a root of unity chosen to have the same order as g. It might seem
improbable that substituting a root of unity into a polynomial with integer
coefficients would have an enumerative meaning. But many instances of the
cyclic sieving phenomenon have now been found. Furthermore, the proofs that
this phenomenon hold often involve interesting and sometimes deep results from
representation theory. We will survey the current literature on cyclic sieving,
providing the necessary background about representations, Coxeter groups, and
other algebraic aspects as needed.Comment: 48 pages, 3 figures, the sedcond version contains numerous changes
suggested by colleagues and the referee. To appear in the London Mathematical
Society Lecture Note Series. The third version has a few smaller change
- …