Conjectural description of the smoothing-component moduli space

About 5 years old · traced to

Assume that DD is negative definite. Let D1,…,DkD_1,\ldots,D_k be the irreducible components of DD, and define

Q=⟨D1,…,Dk⟩⊥⊂Pic⁡Y.Q=\langle D_1,\ldots,D_k\rangle^\perp\subset\operatorname{Pic}Y.

Let C\mathcal{C} be the interior of K(Ygen)‾∩Q\overline{K(Y_{\mathrm{gen}})}\cap Q inside Pic⁡Y⊗R=HdR2(Y;R)\operatorname{Pic}Y\otimes\mathbb{R}=H^2_{dR}(Y;\mathbb{R}), where K(Ygen)K(Y_{\mathrm{gen}}) is the generic Kähler cone; let Φ\Phi be the set of all roots in QQ; and let Adm\mathrm{Adm} be the subgroup of admissible lattice automorphisms of Pic⁡Y\operatorname{Pic}Y preserving the classes [Di][D_i] and C\mathcal{C}. Smoothing-moduli conjecture. There is a natural isomorphism

S≃((QR+iC)\⋃α∈Φ, k∈Z{x∣⟨x,α⟩=k})/(Q⋊Adm).\mathbf{S}\simeq\Big((Q_{\mathbb{R}}+i\mathcal{C})\backslash\bigcup_{\alpha\in\Phi,\ k\in\mathbb{Z}}\{x\mid\langle x,\alpha\rangle=k\}\Big)/(Q\rtimes\mathrm{Adm}).

For k≤5k\leq5, the source says this statement is a theorem of Looijenga; the conjectural status concerns the general cases under discussion.

References

Primary source

Paul Hacking and Ailsa Keating, “Symplectomorphisms of some Weinstein 4-manifolds”, arXiv:2112.06797 (2025).

Progress summary

Never refreshed

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

Solutions 0

No solutions have been posted yet.