An efficient asymmetric removal lemma and its limitations Gishboliner, Lior Shapira, Asaf Wigderson, Yuval The triangle removal states that if G contains edge-disjoint triangles, then G contains triangles. Unfortunately, there are no sensible bounds on the order of growth of , and at any rate, it is known that is not polynomial in . Csaba recently obtained an asymmetric variant of the triangle removal, stating that if G contains edge-disjoint triangles, then G contains copies of . To this end, he devised a new variant of Szemerédi’s regularity lemma. We obtain the following results: • We first give a regularity-free proof of Csaba’s theorem, which improves the number of copies of to the optimal number . • We say that H is -abundant if every graph containing edge-disjoint triangles has copies of H. It is easy to see that a -abundant graph must be triangle-free and tripartite. Given our first result, it is natural to ask if all triangle-free tripartite graphs are -abundant. Our second result is that assuming a well-known conjecture of Ruzsa in additive number theory, the answer to this question is negative. Our proofs use a mix of combinatorial, number-theoretic, probabilistic and Ramsey-type arguments. Cambridge University Press 2025 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_2df8fbb1 https://research-explorer.ista.ac.at/record/22158 Gishboliner L, Shapira A, Wigderson Y. An efficient asymmetric removal lemma and its limitations. <i>Forum of Mathematics, Sigma</i>. 2025;13. doi:<a href="https://doi.org/10.1017/fms.2024.68">10.1017/fms.2024.68</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1017/fms.2024.68 info:eu-repo/semantics/altIdentifier/issn/2050-5094 info:eu-repo/semantics/altIdentifier/arxiv/2301.07693 info:eu-repo/semantics/openAccess