Gewirtz graph as an induced subgraph of triangular graphs

Determine whether the Gewirtz graph, the strongly regular graph with parameters $(n',d',\lambda',\mu')=(56,10,0,2)$, can occur as an induced subgraph of the triangular graph $T_\ell=L(K_\ell)$ for any integer $\ell\geq 32.

Background

The paper studies necessary conditions for a strongly regular graph to occur as an induced subgraph of another strongly regular graph, using both the Lovász ϑ\vartheta-function and graph energy. For triangular graphs TT_\ell, these conditions reduce to two explicit inequalities involving the parameters of a candidate induced strongly regular subgraph.

Applying these inequalities to the Gewirtz graph, which has 56 vertices and strongly regular parameters (56,10,0,2)(56,10,0,2), rules out its occurrence as an induced subgraph of TT_\ell for every 31\ell\leq31. For 32\ell\geq32, both necessary inequalities are satisfied, so the paper leaves unresolved whether an actual induced-subgraph embedding exists.

References

However, for $\ell \geq 32$, this question remains open, as both inequalities in eq1: 19.02.25 hold.

On Strongly Regular Graphs and the Friendship Theorem  (2502.13596 - Sason, 19 Feb 2025) in Section 5, Example "Continuation to Example 5: the Gewirtz graph"