Counting permutations by congruence class of major index (2005)
Barcelo, Helene, Sagan, Bruce, Sundaram, Sheila
Consider S_n, the symmetric group on n letters, and let maj pi denote the major index of a permutation pi in S_n. Given positive integers k,l and nonnegative integers i,j, define m_n^{k,l}(i,j) :=...
On Counting Permutations By Pairs of Congruence (2002)
For a xed positive integer n; let S n denote the symmetric group of n! permutations on n symbols, and let maj() denote the major index of a permutation : Fix positive integers k < ` n; and...
On Counting Permutations By Pairs of Congruence (2002)
For a fixed positive integer n, let S n denote the symmetric group of n! permutations on n symbols, and let maj(#) denote the major index of a permutation #. Fix positive integers k
On counting permutations by pairs of congruence classes of major index (2001)
Barcelo, Helene, Maule, Robert, Sundaram, Sheila
For a fixed positive integer n, let S_n denote the symmetric group of n! permutations on n symbols, and let maj(sigma) denote the major index of a permutation sigma. For positive integers k
On The Topology Of Two Partition Posets With Forbidden Block Sizes (1998)
We study two subposets of the partition lattice obtained by restricting block sizes. The first consists of set partitions of f1; : : : ; ng with block size at most k; for k n Gamma 2: We show that...
On The Topology Of Two Partition Posets With Forbidden Block Sizes (1998)
. We study two subposets of the partition lattice obtained by restricting block sizes. The first consists of set partitions of f1; : : : ; ng with block size at most k; for k n Gamma 2: We show that...
Homotopy Of Non-Modular Partitions And The Whitehouse Module (1998)
We present a class of subposets of the partition lattice Pi n with the following property: The order complex is homotopy equivalent to the order complex of Pi nGamma1 ; and the Sn-module structure of...
Homotopy Of Non-Modular Partitions And The Whitehouse Module (1997)
We present a class of subposets of the partition lattice Pi n with the following property: The order complex is homotopy equivalent to the order complex of Pi nGamma1 ; and the Sn-module structure of...
Group Actions on Arrangements of Linear Subspaces and Applications to Configuration Spaces (1997)
Sheila Sundaram, Volkmar Welker
this paper we develop combinatorial and representation-theoretic methods in the theory of arrangements of linear subspaces in R , which can be applied to the study of the cohomology of spaces of...
The Homology Representations of the k-Equal Partition Lattice (1996)
Sheila Sundaram, Michelle Wachs
this paper are closely related to the character of Sn on the multilinear part of the free Lie algebra. For k = 2 the basis for cohomology provided by the shelling gives an Sn -equivariant filtration...
this paper we consider the Sn -representation on the homology of certain Cohen-Macaulay subposets of Pi n : In Section 1, we present a general technique for manipulating these homology modules. The...
The Homology of Partitions With an Even Number of Blocks (1996)
Let Pi 2n denote the subposet obtained by selecting even ranks in the partition lattice Pi 2n : We show that the homology of Pi 2n has dimension 2 2nGamma1 E 2nGamma1 ; where E 2nGamma1 is the...
Applications of the Hopf trace formula to computing homology representations (1996)
this paper is to illustrate the use of a well-known technique of algebraic topology, the Hopf trace formula, as a tool in computing homology representations of posets. Inspired by a recent paper of...
Plethysm, Partitions with an Even Number of Blocks and Euler Numbers (1996)
This paper is based on an hour address given at the Sixth Conference on Formal Power Series and Algebraic Combinatorics, held at DIMACS in 1994. It is written primarily for an audience of...
Plethysm, Partitions with an Even Number of Blocks and Euler Numbers (1996)
. This paper is based on an hour address given at the Sixth Conference on Formal Power Series and Algebraic Combinatorics, held at DIMACS in 1994. It is written primarily for an audience of...
this paper we consider the Sn -representation on the homology of certain Cohen-Macaulay subposets of Pi n : In Section 1, we present a general technique for manipulating these homology modules. The...
Applications of the Hopf trace formula to computing homology representations (1996)
this paper is to illustrate the use of a well-known technique of algebraic topology, the Hopf trace formula, as a tool in computing homology representations of posets. Inspired by a recent paper of...
The Homology of Partitions With an Even Number of Blocks (1996)
. Let Pi e 2n denote the subposet obtained by selecting even ranks in the partition lattice Pi 2n : We show that the homology of Pi e 2n has dimension (2n)! 2 2nGamma1 E 2nGamma1 ; where E 2nGamma1...
The Homology Representations of the k-Equal Partition Lattice (1995)
Sheila Sundaram, Michelle Wachs
this paper are closely related to the character of Sn on the multilinear part of the free Lie algebra. For k = 2 the basis for cohomology provided by the shelling gives an Sn -equivariant filtration...
On a bijection between Littlewood-Richardson fillings of conjugate shape (1992)
Hanlon, Phil, Sundaram, Sheila
We present a new bijective proof of the equality between the number of Littlewood-Richardson fillings of a skew-shape [lambda]/[mu] of weight [nu], and those of the conjugate skew-shape...
The Cauchy identity for Sp(2n) (1990)
A bijection establishing the Cauchy identity for Sp(2n) is presented, using the insertion algorithm of Berele. A key element in the bijection is a new encoding of up-down tableaux. We present this as...
Orthogonal tableaux and an insertion algorithm for SO(2n + 1) (1990)
A new set of tableaux indexing the weights of the irreducible representations of SO(2n + 1) is presented. These tableaux are used to produce an insertion scheme which gives a combinatorial...
On the combinatorics of representations of Sp(2n,C) (1986)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 1986.
On the combinatorics of representations of Sp(2n,C) /--by Sheila Sundaram. (1986)
Supervised by Richard P. Stanley.
On the combinatorics of representations of Sp(2n,C) (1986)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 1986.