Real critical points conjecture for reciprocal likelihoods of d-pencils

About 6 years old · traced to

Let L\mathcal{L} be a d-pencil, meaning a pencil of quadrics with no zeros in real projective space, and suppose that it has rr distinct eigenvalues. For data s=(s1,…,sn)∈Rns=(s_1,\ldots,s_n)\in\mathbb{R}^n, consider the reciprocal log-likelihood function

ℓ~S(x,y)=∑i=1n(−log⁡(aix+y)−siaix+y).\widetilde{\ell}_S(x,y)=\sum_{i=1}^n\left(-\log(a_i x+y)-\frac{s_i}{a_i x+y}\right).

Real critical points conjecture. There exists s=(s1,…,sn)∈Rns=(s_1,\ldots,s_n)\in\mathbb{R}^n such that ℓ~S\widetilde{\ell}_S has 2r−32r-3 distinct real critical points.

References

Primary source

Claudia Fevola, Yelena Mandelshtam and Bernd Sturmfels, “Pencils of Quadrics: Old and New”, arXiv:2009.04334 (2021).

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.