Dr Panos Giannopoulos
Contact details
Personal links
About
Overview
Panos is a Lecturer in Algorithms/Computational Geometry at the giCentre. His research interests include geometric optimization, approximation algorithms and fixed-parameter (in)tractability.
Research:
Recent (relatively):
Persistent Homology in Medical Image Processing: A Literature Review (ACM ToCH)
One-Sided Local Crossing Minimization (draft)
Near-Linear and Parameterized Approximations for Maximum Cliques in Disk Graphs (SWAT 2026)
Delaunay Triangulations with Predictions (ITCS 2026)
Searching in Euclidean Spaces with Predictions (WAOA 2024)
On k-means for segments and polylines (ESA 2023)
PTAS and Subexponential Algorithm for Maximum Clique on Disk and Unit Ball Graphs (J. ACM, 2021)
Full list here.
Projects:
Fixed-parameter tractability for geometric optimization problems (FptGeom) EPSRC First Grant (2017-2019)
Postdocs:
Edouard Bonnet, 2017 - 2018 (now at ENS-LYON)
PhD students:
- Daniel Brito (City, with C.C. Reyes-Aldasoro)
- Alexandru Chitiga (City, with R. Noble)
- Daniel Werner, 2010-2013 (FU-Berlin)
Qualifications
- Fellow, Higher Education Academy, United Kingdom
- Habilitation, Free University of Berlin, Germany
- PhD, Utrecht University, The Netherlands
- MSc, Imperial College London, United Kingdom
Postgraduate training
- PGCert in HE, Middlesex University, London, United Kingdom
Employment
- Lecturer, City, University London, United Kingdom, 2019 - present
- (Senior) Lecturer, Middlesex University, United Kingdom, 2014 - 2019
- Research Fellow, University of Bayreuth, Germany, 2011 - 2014
- Research Fellow, Free University of Berlin, Germany, 2008 - 2014
Publications
Publications by category
Conference papers and proceedings (13)
- Gao, J., Gawrychowski, P., Giannopoulos, P., Mulzer, W., Singh, S., Staals, F.... Zehavi, M. (2026). Near-Linear and Parameterized Approximations for Maximum Cliques in Disk Graphs. 20th Scandinavian Symposium on Algorithm Theory (SWAT 2026) 17-19 June, Copenhagen, Denmark.doi:10.4230/LIPIcs.SWAT.2026.23
- Gao, J., Gawrychowski, P., Giannopoulos, P., Mulzer, W., Singh, S., Staals, F.... Zehavi, M. Near-Linear and Parameterized Approximations for Maximum Cliques in Disk Graphs. .doi:10.4230/LIPIcs.SWAT.2026.20
- Cabello, S., Chan, T.M., Giannopoulos, P. and Shubhangi, S. (2026). Delaunay Triangulations with Predictions. 17th Innovations in Theoretical Computer Science Conference (ITCS 2026) 26-30 January, Milan, Italy.doi:10.4230/LIPIcs.ITCS.2026.31
- Brito-Pacheco, D., Ibadulla, R., Fernández, X., Giannopoulos, P. and Reyes-Aldasoro, C.C. Persistent Homology and Gabor Features Reveal Inconsistencies Between Widely Used Colorectal Cancer Training and Testing Datasets. .doi:10.1007/978-3-031-98688-8_7
- Cabello, S. and Giannopoulos, P. Searching in Euclidean Spaces with Predictions. .doi:10.1007/978-3-031-81396-2_3
- Brito-Pacheco, D.A., Karabağ, C., Brito-Loeza, C., Giannopoulos, P., Reyes Aldasoro, C.C. and Barry, D. (2024). Morphological Analysis of HeLa Cells and their Mitochondria under Electron Microscopy. Crick BioImage Analysis Symposium 2024 25-26 November, London, UK.
- Brito-Pacheco, D., Karabağ, C., Brito-Loeza, C., Giannopoulos, P. and Reyes-Aldasoro, C.C. (2024). Relationship between Irregularities of the Nuclear Envelope and Mitochondria in HeLa Cells Observed with Electron Microscopy. 2024 IEEE International Symposium on Biomedical Imaging (ISBI) 27-30 May.doi:10.1109/isbi56570.2024.10635639
- Cabello, S. and Giannopoulos, P. (2024). Delaunay Triangulation and Convex Polygons with Predictions. 40th European Workshop on Computational Geometry 13-15 March, Ioannina, Greece.
- Cabello, S. and Giannopoulos, P. (2023). On k-means for segments and polylines. European Symposium on Algorithms (ESA) 4-6 September, CWI Amsterdam, NL.doi:10.4230/LIPIcs.ESA.2023.28
- Giannopoulos, P., Abrahamsen, M., Löffler, M. and Rote, G. Geometric Multicut. 46th International Colloquium on Automata, Languages, and Programming (ICALP 2019)..doi:10.4230/LIPIcs.ICALP.2019.4
- Giannopoulos, P., Bonnet, E., Kim, E.J., Rzazewski, P. and Sikora, F. (2018). QPTAS and Subexponential Algorithm for Maximum Clique on Disk Graphs. 34th International Symposium on Computational Geometry (SoCG 2018) 11-14 July, Budapest, Hungary.doi:10.4230/LIPIcs.SoCG.2018.12
- Giannopoulos, P. and Bonnet, E. (2018). Orthogonal Terrain Guarding is NP-complete. 34th International Symposium on Computational Geometry (SoCG 2018) 11-14 June, Budapest, Hungary.doi:10.4230/LIPIcs.SoCG.2018.11
- Giannopoulos, P., Bonnet, E. and Lampis, M. (2017). On the Parameterized Complexity of Red-Blue Points Separation. 12th International Symposium on Parameterized and Exact Computation (IPEC 2017) 4-8 September, Vienna, Austria.doi:10.4230/LIPIcs.IPEC.2017.8
Journal articles (8)
- Brito-Pacheco, D., Giannopoulos, P. and Reyes-Aldasoro, C.C. (2026). Persistent Homology in Medical Image Processing: A Literature Review. ACM Transactions on Computing for Healthcare. doi:10.1145/3820762
- Bonamy, M., Bonnet, É., Bousquet, N., Charbit, P., Giannopoulos, P., Kim, E.J.... Thomassé, S. (2021). EPTAS and Subexponential Algorithm for Maximum Clique on Disk and Unit Ball Graphs. Journal of the ACM, 68(2), pp. 1-38. doi:10.1145/3433160
- Abrahamsen, M., Giannopoulos, P., Löffler, M. and Rote, G. (2020). Geometric Multicut: Shortest Fences for Separating Groups of Objects in the Plane. Discrete & Computational Geometry, 64(3), pp. 575-607. doi:10.1007/s00454-020-00232-w
- Bonnet, E. and Giannopoulos, P. (2019). Orthogonal Terrain Guarding is NP-complete. Journal of Computational Geometry, 10(2), pp. 21-44. doi:10.20382/jocg.v10i2a3
- Giannopoulos, P., Bonnet, E. and Lampis, M. (2019). On the Parameterized Complexity of Red-Blue Points Separation. Journal of Computational Geometry, 10(1), pp. 181-206. doi:10.20382/jocg.v10i1a7
- Alt, H., Cabello, S., Giannopoulos, P. and Knauer, C. (2017). Minimum Cell Connection in Line Segment Arrangements. International Journal of Computational Geometry & Applications, 27(03), pp. 159-176. doi:10.1142/s0218195917500017
- Cabello, S. and Giannopoulos, P. (2016). The Complexity of Separating Points in the Plane. Algorithmica, 74(2), pp. 643-663. doi:10.1007/s00453-014-9965-6
- Giannopoulos, P., Knauer, C., Rote, G. and Werner, D. (2013). Fixed-parameter tractability and lower bounds for stabbing problems. Computational Geometry, 46(7), pp. 839-860. doi:10.1016/j.comgeo.2011.06.005
Professional activities
Editorial activity (5)
- IPEC 2024, PC member, 2024.
- EWCG 2023, Programme Committee Member, January - March 2023.
- Young Researchers Forum, SoCG 2019, Programme Commitee Member, March - July 2019.
- EWCG 2018, Programme Committee Member, 2018.
- Multimedia Track, SoCG 2012, Programme Committee Member, 2012.