Math-5173 · mathematics · Combinatorics

Math-5173

A downgrade criterion for clique-order monotonicity

Status Partially solved · unsolvedmath.comLLM status Open unverified

Top Open Problems Not reported cataloguedPartially solvedOpen

Statement

Definitions and mathematical statement

For finite simple graphs, $G\xrightarrow r K_k$ means that every $r$-edge-coloring of $G$ contains a monochromatic $K_k$. Under the standard Ramsey-minimal convention, no proper subgraph has this property. Let $\mathcal M_r(k)$ be those graphs and \[ s_r(k)=\min\{\delta(G):G\in\mathcal M_r(k)\}. \] The source's minimality line instead prints $G-e\not\xrightarrow r K_3$, inconsistent with its $K_k$ target. The aid explicitly corrects $K_3$ to $K_k$. Moreover edge-minimality alone must exclude isolated vertices: otherwise adding one makes the displayed minimum zero. The proper-subgraph convention, or equivalent edge-minimality without isolates, is essential to the intended nontrivial parameter.

The conjecture, attributed to Fox--Grinshpun--Liebenau--Person--Szabó and presented by Tibor Szabó, is \[ s_r(k)\leq s_r(k+1) \] for clique orders $k$ and fixed number of colors $r$. The source reports $s_2(k)=(k-1)^2$, attributed there to Erdős--Burr--Lovász (1976), and, asymptotically in large $r$, \[ \Omega(r^2\log r)\leq s_r(3)\leq O(r^2(\log r)^2), \] \[ \Omega\left(\frac{r^2\log r}{\log\log r}\right)\leq s_r(k) \leq O\left(r^2(\log r)^{8(k-1)^2}\right)\quad(k\geq4). \] Dependence of constants on a fixed clique order must be retained; these displays are not small-$r$ numerical bounds.

For the aid's packing reduction, let $P_r(j)$ be the least size of a common vertex set supporting edge-disjoint $K_{j+1}$-free graphs $G_1,\ldots,G_r$ such that every vertex $r$-coloring produces a $K_j$ in $G_i$ all of whose vertices have color $i$, for some $i$. The invoked packing identity is $s_r(k)=P_r(k-1)$. Hence the adjacent conjecture is equivalent to $P_r(k-1)\leq P_r(k)$.

The reported sufficient local downgrade certificate is this: take an optimal $P_r(k)$ witness and, in every $G_i$, find a spanning $K_k$-free subgraph retaining a $K_{k-1}$ inside every original $K_k$. These subgraphs form a $P_r(k-1)$ witness on the same vertex set. A concrete sufficient condition is an exact vertex $K_k$-transversal in each color graph, meaning a set meeting every $K_k$ in exactly one vertex; deleting incident edges at those vertices preserves the required $(k-1)$-cliques. The aid does not prove that every optimal packing has such a certificate.

Independently, the summary invokes monotonicity in the number of colors and explicit bounds to compare sufficiently separated clique sizes. For example, any valid upper bound $s_r(k)\leq B(r,k)$ gives \[ (\ell-1)^2\geq B(r,k)\quad\Longrightarrow\quad s_r(k)\leq B(r,k)\leq s_2(\ell)\leq s_r(\ell),\qquad r\geq2. \] This is a separated-size comparison, not the adjacent inequality; the record supplies no fully numerical universal separation threshold. The general adjacent conjecture for $r\geq3$ remains open in the aid's checked-literature assessment, which is not independently updated here.

Short English statement

The intended parameter uses true Ramsey-minimal graphs; the source has a clique-index typo and also needs an isolated-vertex convention. The aid gives a packing-witness condition sufficient for adjacent monotonicity and a separate comparison for widely separated clique sizes. It does not settle the general adjacent conjecture.

Sources

  • Local UnsolvedMath registry, permanent ID $20000933$, source code catalogue entry, complete supplied source snapshot and research summary.
  • AIM workshop Graph Ramsey theory, Ramsey minimal graphs, Problem 11, presented by Tibor Szabó, supplied Overleaf source https://www.overleaf.com/read/mnvcscjjysvg; canonical local record aim-combinatorics-notes.json, notes[57].
  • Conjecture attributed to Fox--Grinshpun--Liebenau--Person--Szabó; two-color formula attributed in the source to Erdős--Burr--Lovász, 1976. No full bibliographic entries for these, the packing identity or the asymptotic bounds are supplied; the original literature field is empty.
  • Research attempt 1: partial result; problem open at the recorded run, registry status partially solved; supplied rigor label "proved", novelty confidence "low". The machine-generated aid is not peer reviewed and requires independent verification before citation.

Catalogue entry

Statement licence: CC-BY-4.0 · Source file

Contributions 0

No attempts yet. Significant partial results and substantial reductions are welcome. Contribute an attempt.