English

On the Multi-Interval Ulam-R\'enyi Game: for 3 lies 4 intervals suffice

Combinatorics 2018-07-03 v2

Abstract

We study the problem of identifying an initially unknown mm-bit number by using yes-no questions when up to a fixed number ee of the answers can be erroneous. In the variant we consider here questions are restricted to be the union of up to a fixed number of intervals. For any e1e \geq 1 let kek_e be the minimum kk such that for all sufficiently large mm, there exists a strategy matching the information theoretic lower bound and only using kk-interval questions. It is known that ke=O(e2)k_e = O(e^2). However, it has been conjectured that the ke=Θ(e).k_e = \Theta(e). This linearity conjecture is supported by the known results for small values of ee. For e2e\leq2 we have ke=e.k_e = e. We extend these results to the case e=3e=3. We show k34k_3 \leq 4 improving upon the previously known bound k310.k_3 \leq 10.

Keywords

Cite

@article{arxiv.1708.08738,
  title  = {On the Multi-Interval Ulam-R\'enyi Game: for 3 lies 4 intervals suffice},
  author = {Ferdinando Cicalese and Massimiliano Rossi},
  journal= {arXiv preprint arXiv:1708.08738},
  year   = {2018}
}

Comments

31 pages, 5 figures, extension of the result to non-asymptotic strategies