Peer-reviewedCC BY 4.0Algebraic Combinatorics
Counting points on Hessenberg varieties over finite fields
- 1Instituto de Matemática e Estatística, Universidade Federal Fluminense, Niterói, Rio de Janeiro (Brazil)
- 2Indraprastha Institute of Information Technology Delhi, New Delhi (India)
Abstract
We give a counting formula in terms of modified Hall–Littlewood polynomials and the chromatic quasisymmetric function for the number of points on an arbitrary Hessenberg variety over a finite field. As a consequence, we express the Poincaré polynomials of complex Hessenberg varieties in terms of a Hall scalar product involving the symmetric functions above. We use these results to give a new proof of a combinatorial formula for the modified Hall–Littlewood polynomials.
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BibTeX
@article{abreu2026counting,
title = {{Counting points on Hessenberg varieties over finite fields}},
author = {Alex Abreu and Antonio Nigro and Samrith Ram},
journal = {Algebraic Combinatorics},
year = {2026},
month = oct,
doi = {10.5802/alco.519},
url = {https://alco.centre-mersenne.org/articles/10.5802/alco.519/},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Counting points on Hessenberg varieties over finite fields
AU - Alex Abreu
AU - Antonio Nigro
AU - Samrith Ram
PY - 2026
DA - 2026/10/27
JO - Algebraic Combinatorics
DO - 10.5802/alco.519
UR - https://alco.centre-mersenne.org/articles/10.5802/alco.519/
AB - We give a counting formula in terms of modified Hall–Littlewood polynomials and the chromatic quasisymmetric function for the number of points on an arbitrary Hessenberg variety over a finite field. As a consequence, we express the Poincaré polynomials of complex Hessenberg varieties in terms of a Hall scalar product involving the symmetric functions above. We use these results to give a new proof of a combinatorial formula for the modified Hall–Littlewood polynomials.
SN - 2589-5486
ER -