Sn-equivariant L-classes of Cartesian powers of Witt spaces and the Hodge index conjecture for symmetric products
Abstract
For a compact oriented even-dimensional Witt pseudomanifold X, we compute the Sn-equivariant Banagl--Zagier L-classes of Xn in terms of the Goresky--MacPherson L-classes of X and the intersection cohomology Euler characteristic of X. This generalizes a theorem of Zagier for manifolds. Our approach is based on analyzing the equivariant structure of the signature operator of Xn using equivariant KK-theory and power operations in analytic K-homology. We establish an analytic K-homology analogue of Moonen's algebraic localization theorem by proving that the localized Chern character of the n-th power operation, evaluated at an n-cycle, agrees with the n-th homological Adams operation applied to the Chern character. As an application, we prove that the characteristic class Hodge index conjecture for singular varieties, formulated by Brasselet--Schürmann--Yokura, is preserved under taking symmetric products of complex projective varieties.
Related
BibTeX
@misc{aligholi2026snequivariant,
title = {{$S_n$-equivariant $L$-classes of Cartesian powers of Witt spaces and the Hodge index conjecture for symmetric products}},
author = {Mohammadali Aligholi},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.02577},
eprint = {2611.02577},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.02577},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - S_n-equivariant L-classes of Cartesian powers of Witt spaces and the Hodge index conjecture for symmetric products
AU - Mohammadali Aligholi
PY - 2026
DA - 2026/11/02
PB - arXiv
DO - 10.48550/arxiv.2611.02577
UR - https://arxiv.org/abs/2611.02577
AB - For a compact oriented even-dimensional Witt pseudomanifold X, we compute the S_n-equivariant Banagl--Zagier L-classes of X^n in terms of the Goresky--MacPherson L-classes of X and the intersection cohomology Euler characteristic of X. This generalizes a theorem of Zagier for manifolds. Our approach is based on analyzing the equivariant structure of the signature operator of X^n using equivariant KK-theory and power operations in analytic K-homology. We establish an analytic K-homology analogue of Moonen's algebraic localization theorem by proving that the localized Chern character of the n-th power operation, evaluated at an n-cycle, agrees with the n-th homological Adams operation applied to the Chern character. As an application, we prove that the characteristic class Hodge index conjecture for singular varieties, formulated by Brasselet--Schürmann--Yokura, is preserved under taking symmetric products of complex projective varieties.
ER -