#### Filter Results:

- Full text PDF available (11)

#### Publication Year

1983

2008

#### Publication Type

#### Co-author

#### Publication Venue

Learn More

- Gail Letzter
- 2002

We study the space of biinvariants and zonal spherical functions associated to quantum symmetric pairs in the maximally split case. Under the obvious restriction map, the space of biinvariants is proved isomorphic to the Weyl group invariants of the character group ring associated to the restricted roots. As a consequence, there is either a unique set, or… (More)

- Gail Letzter
- 1999

Coideal subalgebras of the quantized enveloping algebra are surveyed , with selected proofs included. The first half of the paper studies generators, Harish-Chandra modules, and associated quantum homogeneous spaces. The second half discusses various well known quantum coideal subalgebras and the implications of the abstract theory on these examples. The… (More)

- Gail Letzter
- 2008

It is possible to develop a unified theory of quantum symmetric pairs based on a characterization of left coideal subalgebras in the quantized enveloping algebra, which are maximal with respect to specializing (in the limit) to the classical algebra fixed under an involu-tion. Previous work established an appropriate framework for quantum zonal spherical… (More)

- Gail Letzter
- 2004

This is the first paper in a series of two which proves a version of a theorem of Harish-Chandra for quantum symmetric spaces in the maximally split case: There is a Harish-Chandra map which induces an isomorphism between the ring of quantum invariant differential operators and the ring of invariants of a certain Laurent polynomial ring under an action of… (More)

We analyze the centralizer of the Macdonald difference operator in an appropriate algebra of Weyl group invariant difference operators. We show that it coincides with Cherednik's commuting algebra of difference operators via an analog of the Harish-Chandra isomorphism. Analogs of Harish-Chandra series are defined and realized as solutions to the system of… (More)

As is well known, the Shapovalov bilinear form and its determinant is an important tool in the representation theory of semisimple Lie algebras over char. 0. To our knowledge, the corresponding study of the Shapovalov bilinear form and its determinant is not available in the literature in char. p or the quantum case at roots of unity. The aim of this paper… (More)

- Stefan Kolband, Gail Letzter
- 2006

The theory of quantum symmetric pairs as developed by the second author is based on coideal subalgebras of the quantized universal enveloping algebra for a semisimple Lie algebra. This paper investigates the center of these coideal subalgebras, proving that the center is a polynomial ring. A basis of the center is given in terms of a sub-monoid of the… (More)

- Gail Letzter
- 2004

The two papers in this series analyze quantum invariant differential operators for quantum symmetric spaces in the maximally split case. In this paper, we complete the proof of a quantum version of Harish-Chandra's theorem: There is a Harish-Chandra map which induces an isomorphism between the ring of quantum invariant differential operators and a ring of… (More)

- Dave Witte Morris, Gail Letzter, Joseph A. Gallian
- Discrete Mathematics
- 1983

Hadamard matrices are defined, and their basic properties outlined. A survey of historical and recent literature follows, in which a number of existence theorems are examined and given context. Finally , a new result for Hadamard matrices over Z 2 is presented and given a graph-theoretic interpretation.