Modified Bronowski conjecture on identifiability and secant-variety degree

At least 3 years old · documented by

Let X⊂PNX\subset\mathbb{P}^N be an irreducible and non-degenerate variety. Let Sech(X)\mathbb{S}ec_h(X) denote the Zariski closure of the union of the (h−1)(h-1)-planes spanned by hh points of XX, and set

ch=codim⁡PN(Sech(X)).c_h=\operatorname{codim}_{\mathbb{P}^N}(\mathbb{S}ec_h(X)).

A variety of minimal degree has the smallest possible degree for its codimension.

Modified Bronowski conjecture. If a general (h−1)(h-1)-tangential projection of XX is birational and its image is a variety of minimal degree, then XX is hh-identifiable and

deg⁡Sech(X)=(h+chh).\deg\mathbb{S}ec_h(X)=\binom{h+c_h}{h}.

The degree in the conclusion is the smallest possible degree of the hh-secant variety. The conjecture was proposed as a modification of Bronowski's conjecture and is implied by the original conjecture, but the paper gives counterexamples to both statements.

References

Primary source

Alex Massarenti and Massimiliano Mella, “Bronowski's conjecture and the identifiability of projective varieties”, arXiv:2210.13524 (2024).

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.