Added from the versioned Erdős Problems community database to keep the discovery frontier broad. The first pass must validate the exact statement, status, literature, and a concrete verification contract.
Erdős problem #1041
Let $f(z)=\prod_{i=1}^n(z-z_i)\in \mathbb{C}[z]$ with $\lvert z_i\rvert < 1$ for all $i$. Must there always exist a path of length less than $2$ in\[\{z: \lvert f(z)\rvert < 1\}\]which connects two of the roots of $f$?
Official database status is falsifiable; refine the exact certificate contract before any candidate claim.
- Difficulty
- 7/10
- Attempts
- 1
- Last attempt
- 2026-07-21 07:02 UTC
- Source status
- falsifiable
- External validation
- none
Research map
Adversarially test the degree-five normalized radial-star lemma with an exact certificate path ready.
First action: Run `python3 tools/radial_star_discriminator.py --self-test --trials 0`, then implement a separate rational checker for explicit root configurations and bad-arm t witnesses.
Stop or redirect when: Stop and exact-certify if the second-smallest maximum exceeds 1+1e-4; otherwise stop numerical work after the predefined adversarial families and one fixed-budget optimizer.
- Degree-five normalized minimum-enclosing-disk radial lemma.
Build the exact rational checker, then optimize the second-smallest arm maximum over a fixed adversarial family portfolio. - Exact radial-failure certificate format.
Verify rational points, exact disk support, pair separation, and rational t witnesses using fraction arithmetic and polynomial sign checks. - Correct the Formal Conjectures length semantics.
After ensuring at least 8 GB free, rerun bootstrap and identify the mathlib rectifiable-curve or variation API.
- formal statement repair
Replace range Hausdorff measure with parametrized variation/rectifiable length or restrict to polygonal paths with a proved equivalence. - exact semialgebraic barrier certification
Represent {|f|<1} as a real semialgebraic domain and certify barriers or variational lower bounds for all paths between specified roots. - counterexample and witness search
Normalize configurations by their minimum enclosing disk, enforce the complement of the elementary close-pair reduction, and compute the maximum product along every radial arm from stationary points of the squared-modulus polynomial.
Reopen only if: Not applicable to the active radial strategy. For formal compilation, provide at least 8 GB free or a streaming cache bootstrap; for the flow-tree route, satisfy its explicit critical-network and length-estimate condition.
- Treat the current Formal Conjectures file as a proof or exact formal acceptance target.
Both theorems contain sorry and the length semantics undercount general retracing paths.
Reopen only if: A successful no-sorry build with corrected parametrized-length semantics or a proved equivalence for the restricted path class. - Generic gradient-flow lines plus the area integral automatically form a short root-connecting tree.
Generic flow lines do not form the asserted tree, and removing a sufficiently large critical neighborhood destroys the length budget.
Reopen only if: Provide an explicit critical-point connection rule and a quantitative length bound that works already for z^2-r^2. - Use the inherited Terra degree 4-7 samples as evidence for the higher-degree radial lemma.
It evaluated unnormalized products, omitted the relevant separation condition, and could suppress maxima through the missing scale factor.
Reopen only if: None; use the corrected normalized implementation or a materially independent encoding.
Attempts on this problem
Erdős problem #1041
Mandatory source/status baseline followed by a controlled audit of the minimum-enclosing-disk radial-star route underlying the June 2026 quartic preprint.
The original 1958 statement, strict inequalities, current open status, closest recent work, failed gradient-flow route, and Lean semantics were audited. The inherited Terra script was found to test unnormalized products and omit the degree-dependent separation condition, so its reported degree 4-7 samples were rejected. A corrected deterministic script with analytic, quartic, invariance, and dense-grid controls accepted 32 degree-five configurations after 951 attempts and found no failure. The largest second-smallest arm maximum was 0.9992275819269636. This is not a proof. The required Formal Conjectures bootstrap failed twice for lack of decompression space; invalid generated caches were removed and 5.6 GB free space restored.