Hartshorne conjecture for varieties of lines

At least 16 years old · documented by

Let X⊂PNX\subset\mathbb{P}^N be a smooth irreducible non-degenerate variety of dimension nn covered by lines. For a general point x∈Xx\in X, let Lx⊂Pn−1\mathcal{L}_x\subset\mathbb{P}^{n-1} denote the variety of lines through xx, and let T=⟨Lx⟩⊆Pn−1T=\langle\mathcal{L}_x\rangle\subseteq\mathbb{P}^{n-1}. Hartshorne conjecture for varieties of lines. If dim⁡(Lx)⩾n−12\dim(\mathcal{L}_x)\geqslant\frac{n-1}{2} and dim⁡(Lx)>2codim⁡T(Lx)\dim(\mathcal{L}_x)>2\operatorname{codim}_T(\mathcal{L}_x), then Lx⊂Pn−1\mathcal{L}_x\subset\mathbb{P}^{n-1} is a complete intersection. The conjecture is a proposed reduction of the Fano Hartshorne problem to the geometry of varieties of lines; the source gives some classes in which it is known, but does not resolve it in general.

References

Primary source

Paltin Ionescu and Francesco Russo, “Manifolds covered by lines, defective manifolds and a restricted Hartshorne Conjecture”, arXiv:0909.2763 (2012).

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.