Characteristic-cycle isomorphism conjecture for top category O

From papers

Let A(v,w)\mathfrak{A}(\mathbf v,\mathbf w) be the attracting locus above, let dd denote its expected relevant dimension, let φ\varphi be an integral parameter, and let Otop(v,w)\mathcal O_{\operatorname{top}}(\mathbf v,\mathbf w) be the quotient of O(CBφ(v,w))\mathcal O(\mathsf{CB}_{\varphi}(\mathbf v,\mathbf w)) by objects of Gelfand–Kirillov dimension less than dd. The characteristic-cycle map sends a class in this quotient to its top Borel–Moore homology class.

Characteristic-cycle conjecture. One has

dimA(v,w)=d,\dim \mathfrak{A}(\mathbf v,\mathbf w)=d,

and, for any integral φ\varphi, the map

vKC(Otop(v,w))vH2dBM(A(v,w))\bigoplus_{\mathbf v}K_{\mathbb C}(\mathcal O_{\operatorname{top}}(\mathbf v,\mathbf w))\longrightarrow \bigoplus_{\mathbf v}H^{BM}_{2d}(\mathfrak{A}(\mathbf v,\mathbf w))

induced by characteristic cycles is an isomorphism of vector spaces.

The conjecture would identify the representation obtained from the top quotient of category O\mathcal O with the top Borel–Moore homology representation. The source presents it as the remaining step in reducing the preceding generalized geometric Satake conjecture and gives no resolution.

Progress summary

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Sources & referencesView supporting material

Primary source

Joel Kamnitzer, Ben Webster, Alex Weekes and Oded Yacobi, “Lie algebra actions on module categories for truncated shifted Yangians”, arXiv:2203.12429 (2023).

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