Raul Lopes
Postdoc in Computer Science

Articles and pre-prints

  1. 19. Finding subdigraphs in digraphs of bounded directed treewidth. R. Lopes and I. Sau. http://arxiv.org/abs/2508.13830. Short version to appear in Proc. of the XIII Latin and American Algorithms, Graphs and Optimization Symposium (LAGOS), 2025.

  2. 18. Revisiting Directed Disjoint Paths on tournaments (and relatives). G. C. M. Gomes, R. Lopes, and I. Sau. http://arxiv.org/abs/2504.19957. Short version in Proc. of the 52nd International Colloquium on Automata, Languages and Programming (ICALP), volume 334 of LIPIcs, pages 90:1–90:20, 2025.

  3. 17. Disjoint Temporal Walks Under Waiting Time Constraints. A. Ibiapina, R. Lopes, A. Marino, and A. Silva. https://arxiv.org/abs/2503.02694. Short version in Proc. of the 14th International Conference on Algorithms and Complexity (CIAC), volume 15680 of Lecture Notes in Computer Science, pages 87–103, 2025. Full version to be submitted.

  4. 16. Blow-ups and extensions of trees in tournaments. P. Aboulker, F. Havet, W. Lochet, R. Lopes, L. Picasarri-Arrieta, and C. Rambaud. https://arxiv.org/abs/2410.23566. Currently under review.

  5. 15. Constant congestion linkages in polynomially strong digraphs in polynomial time. R. Lopes and I. Sau. https://arxiv.org/abs/2409.03873. Full version in Discrete Mathematics (DM), volume 349 (2), 2025. doi: 10.1016/j.disc.2025.114808

  6. 14. Finding forest-orderings of tournaments is NP-complete. P. Aboulker, G. Aubian, and R. Lopes. https://arxiv.org/abs/2402.10782. Currently under review.

  7. 13. Clique number of tournaments. P. Aboulker, G. Aubian, P. Charbit, and R. Lopes. https://arxiv.org/abs/2310.04265. Currently under review.

  8. 12. New Menger-like dualities in digraphs and applications to half-integral linkages. V. Campos, J. Costa, R. Lopes, and I. Sau. https://arxiv.org/abs/2306.16134. Short version in Proc. of the 31st Annual European Symposium on Algorithms (ESA), volume 274 of LIPIcs, pages 30:1--30:18, 2023. doi: 10.4230/LIPIcs.ESA.2023.30. Full version in ACM Transactions on Algorithms (TALG), 21(3): 26, pp 1–28, 2025.

  9. 11. On Computing Large Temporal (Unilateral) Connected Components. I. Lopes Costa, R. Lopes, A. Marino, and A Silva. https://arxiv.org/abs/2302.12068. Short version in Proc. of the 34th International Workshop on Combinatorial Algorithms (IWOCA), volume 13889 of LNCS, pages 282--293, 2023. doi: 10.1007/978–3-031–34347–6\_24. Full version in Journal of Computer and System Sciences (JCSS), volume 144, 2024. doi: 10.1016/j.jcss.2024.103548.

  10. 10. Menger’s Theorem for Temporal Paths (Not Walks). A. Ibiapina, R. Lopes, A. Marino, A. Silva. https://arxiv.org/abs/2206.15251. Currently under review.

  11. 9. Twin-width VIII: delineation and win-wins. É. Bonnet, D. Chakraborty, E. Kim, N. Köhler, R. Lopes, and S. Thomassé. https://arxiv.org/abs/2204.00722. Short version in Proc. of the 17th International Symposium on Parameterized and Exact Computation (IPEC), pages 9:1--9:18, 2022. doi: 10.4230/LIPIcs.IPEC.2022.9. Full version to be submitted.

  12. 8. Parameterized algorithms for Steiner Tree and Dominating Set: bounding the leafage by the vertex leafage. C. M. H. de Figueiredo, R. Lopes, A. A. de Melo, and A. Silva. Short version in Proc. of the 16th International Conference and Workshops on Algorithms and Computation (WALCOM), pages 251--262, 2022. doi: 10.1007/978–3-030–96731–4\_21. Full version in Networks, 2024. doi: 10.1002/net.22220.

  13. 7. From branchings to flows: a study of an Edmonds' like property to arc-disjoint branching flows. C. Carvalho, J. Costa, C. Sales, R. Lopes, A. K. Maia, and N. Nisse. https://hal.inria.fr/hal-03031759. Full version in Discrete Mathematics and Theoretical Computer Science (DMTCS), volume 25 (1), 2023. doi: 10.46298/dmtcs.9302.

  14. 6. Coloring problems on bipartite graphs of small diameter. V. Campos, G. Gomes, A. Ibiapina, R. Lopes, I. Sau, and A. Silva. https://arxiv.org/abs/2004.11173. Full version in Electronic Journal of Combinatorics (E-JC), volume 28 (2), 2021. doi: 10.37236/9931.

  15. 5. Edge-disjoint branchings in temporal graphs. V. Campos, R. Lopes, A. Marino, and A. Silva. https://arxiv.org/abs/2002.12694. Short version in Proc. of the 31st International Workshop on Combinatorial Algorithms (IWOCA), volume 12126 of LNCS, pages 112–115, 2020. doi: 10.1007/978–3-030–48966–3\_9. Full version in Electronic Journal of Combinatorics (E-JC), volume 28 (4), 2021. doi: 10.37236/10229.

  16. 4. A relaxation of the Directed Disjoint Paths problem: a global congestion metric helps. R. Lopes and I. Sau. https://arxiv.org/abs/1909.13848. Short version in Proc. of the 45th International Symposium on Mathematical Foundations of Computer Science (MFCS), volume 170 of LIPIcs, pages 68:1–68:15, 2020. Full version in Theoretical Computer Science (TCS), volume 898, pages 75–91, 2022. doi: 10.1016/j.tcs.2021.10.023.

  17. 3. Adapting the Directed Grid Theorem into an FPT algorithm. V. Campos, R. Lopes, A. K. Maia, and I. Sau. https://arxiv.org/abs/2007.07738. Short version in Proc. of the X Latin and American Algorithms, Graphs and Optimization Symposium (LAGOS), volume 346 of ENTCS, pages 229–240, 2019. doi: 10.1016/j.entcs.2019.08.021. Full version in SIAM Journal on Discrete Mathematics (SIDMA), volume 36 (3), 2022. doi: 10.1137/21M1452664.

  18. 2. Bispindles in strongly connected digraphs with large chromatic number. F. Havet, N. Cohen, R. Lopes, and W. Lochet. https://arxiv.org/abs/1703.02230. Short version in Proc. of the IX Latin and American Algorithms, Graphs and Optimization Symposium (LAGOS), volume 62 of ENTCS, pages 69–74, 2017. doi: 10.1016/j.endm.2017.10.013. Full version in Electronic Journal of Combinatorics (E-JC), volume 25 (2), 2018. doi: 10.37236/6922.

  19. 1. A proof for a conjecture of Gorgol. V. Campos and R. Lopes. Short version in Proc. of the VIII Latin and American Algorithms, Graphs and Optimization Symposium (LAGOS), volume 50 of ENTCS, pages 367–372, 2015. doi: 10.1016/j.endm.2015.07.061. Full version in Discrete Applied Mathematics (DAM), volume 245, pages 202--207, 2018. doi: 10.1016/j.dam.2017.04.012