Paszkiewicz's conjecture on products of decreasing positive contractions

About 2 years old · traced to

Let HH be a separable infinite-dimensional Hilbert space, and let T1≥T2≥…T_1\ge T_2\ge\dots be a sequence of positive linear contractions on HH. Define

Sn:=TnTn−1⋯T1.S_n:=T_nT_{n-1}\cdots T_1.

Paszkiewicz's conjecture. The sequence (Sn)(S_n) converges strongly.

This conjecture concerns strong convergence of products of a decreasing sequence of positive contractions. The paper proves the conjecture; the stronger equivalent formulation is that, if T:=lim⁡n→∞TnT:=\lim_{n\to\infty}T_n in the strong operator topology and P:=1{1}(T)P:=1_{\{1\}}(T), then SnS_n converges to PP in the ∗*-strong topology.

References

Primary source

Hiroshi Ando, Yuki Miyamoto and Narutaka Ozawa, “Proof of the Paszkiewicz's conjecture about a product of positive contractions”, arXiv:2405.10770 (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.