English

Neutral-fermionic presentation of the $K$-theoretic $Q$-function

Rings and Algebras 2021-09-29 v5 Representation Theory

Abstract

We show a new neutral-fermionic presentation of Ikeda-Naruse's KK-theoretic QQ-functions, which represent a Schubert class in the KK-theory of coherent sheaves on the Lagrangian Grassmannian. Our presentation provides a simple description and yields straightforward proof of two types of Pfaffian formulas for them. We present a dual space of GΓG\Gamma, the vector space generated by all KK-theoretic QQ-functions, by constructing a non-degenerate bilinear form that is compatible with the neutral fermionic presentation. We give a new family of dual KK-theoretic QQ-functions, their neutral-fermionic presentations, and Pfaffian formulas.

Keywords

Cite

@article{arxiv.1904.02279,
  title  = {Neutral-fermionic presentation of the $K$-theoretic $Q$-function},
  author = {Shinsuke Iwao},
  journal= {arXiv preprint arXiv:1904.02279},
  year   = {2021}
}

Comments

27 pages, 1 figure v4: Major revision. The title has been changed. (The old title was "Pfaffian formulas in K-theory and the Boson-Fermion Correspondence")

R2 v1 2026-06-23T08:28:45.366Z