My Research
My name is Tomáš Masařík and I am an assistant professor at the Institute of Informatics at the The Faculty of Mathematics, Informatics and Mechanics of the University of Warsaw. I participate in the project CUTACOMBS supervised by Marcin Pilipczuk.
Before, I was a postdoctoral fellow at the Simon Fraser University supervised by Bojan Mohar and Ladislav Stacho and at the University of Warsaw in the project CUTACOMBS supervised by Marcin Pilipczuk and in the project BOBR supervised by Michał Pilipczuk.
I obtained PhD at the Department of Applied Mathematics of the Faculty of Mathematics and Physics at the Charles University, Prague, Czech Republic under the supervision of Jiří Fiala. I was also affiliated with the Computer Science Institute of Charles University and I participated in the Center of Excellence - Institute for Theoretical Computer Science.
My research interests are in Graph Theory: mostly coloring problems, stuctural graph theory, algorithms, computational complexity, and parameterized complexity. A list of my publications is also presented at Google Scholar and Orcid. My preprints are usually available at arXiv.
Papers
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On the Uncrossed Number of Graphs (M. Balko, P. Hliněný, TM, J. Orthaber, B. Vogtenhuber, M.H. Wagner):
- Accepted to GD 2024
- ArXiv version.
- Finding Diverse Solutions Parameterized by Cliquewidth (K. Drabik, TM):
- Proper Rainbow Saturation Numbers for Cycles (A. Halfpap, B. Lidický, TM):
- Treewidth is Polynomial in Maximum Degree on Graphs Excluding a Planar Induced Minor (É. Bonnet, J. Hodor, T. Korhonen, TM):
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A Generalised Theory of Proportionality in Collective Decision Making (TM, G. Pierczyński, P. Skowron):
- Manuscript name: Group Fairness in Social Choice.
- Accepted at EC 2024
- ArXiv version.
- Presented at Warsaw–Krakow WKRECAI seminar 2024 (presentation).
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Minimizing an Uncrossed Collection of Drawings (P. Hliněný, TM):
- Accepted to GD 2023
- ArXiv version.
-
Maximum Weight Independent Set in Graphs with no Long Claws in Quasi-Polynomial Time (P. Gartland, D. Lokshtanov, TM, Ma. Pilipczuk, Mi. Pilipczuk, P. Rzążewski):
- STOC 2024 (Proceedings, 25 min recording on youtube, 35 min longer recording, long slides).
- ArXiv version.
- HALG 2024 poster.
- Random Embeddings of Graphs: The Expected Number of Faces in Most Graphs is Logarithmic (J. Campion Loth, K. Halasz, TM, B. Mohar, R. Šámal):
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Proving a Directed Analogue of the Gyárfás-Sumner Conjecture for Orientations of P_4 (L. Cook, TM, Ma. Pilipczuk, A. Reinald, U.S. Souza):
- Journal: The Electronic Journal of Combinatorics.
- ArXiv version.
- Presented at Dagstuhl Workshop 2022 (presentation).
- On Weighted Graph Separation Problems and Flow-augmentation (E.J. Kim, TM, Ma. Pilipczuk, R. Sharma, M. Wahlström):
- A Tight Quasi-polynomial Bound for Global Label Min-Cut (L. Jaffke, P.T. Lima, TM, Ma. Pilipczuk, U.S. Souza):
- Fixed-parameter Tractability of Directed Multicut with Three Terminal Pairs Parameterized by the Size of the Cutset: Twin-width Meets Flow-augmentation (M. Hatzel, L. Jaffke, P.T. Lima, TM, Ma. Pilipczuk, R. Sharma, M. Sorge):
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Max Weight Independent Set in Graphs with no Long Claws: An Analog of the Gyárfás' Path Argument (K. Majewski, TM, J. Novotná, K. Okrasa, Ma. Pilipczuk, P. Rzążewski, M. Sokołowski):
- ICALP 2022(proceedings).
- ArXiv version.
- Presented at UW seminar & HU Berlin 2022 (presentation).
- List Locally Surjective Homomorphisms in Hereditary Graph Classes (P. Dvořák, M. Krawczyk, TM, J. Novotná, P. Rzążewski, A. Żuk):
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Single-conflict Colorings of Degenerate Graphs (P. Bradshaw, TM):
- Journal: Journal of Graph Theory.
- ArXiv version.
- Also presented at Shanghai seminar 2021 (presentation, recording (60 mins) - both P. Bradshaw).
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Linear Bounds for Cycle-free Saturation Games (S. English, TM, G. McCourt, E. Meger, M.S. Ross, S. Spiro):
- Journal: The Electronic Journal of Combinatorics.
- ArXiv version.
- Presented also at Cycles and Colourings 2023 (presentation).
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Tuza's Conjecture for Threshold Graphs (M. Bonamy, Ł. Bożyk, A. Grzesik, M. Hatzel, TM, J. Novotná, K. Okrasa):
- Journal: Discrete Mathematics & Theoretical Computer Science.
- Eurocomb 2021 (proceedings, presentation - J. Novotná).
- ArXiv version.
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Robust Connectivity of Graphs on Surfaces (P. Bradshaw, TM, J. Novotná, L. Stacho):
- Journal: SIAM Journal on Discrete Mathematics (SIDMA).
- Eurocomb 2021 (proceedings, presentation).
- ArXiv version.
- Also presented at CSGT 2022 (presentation).
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Constant Congestion Brambles in Directed Graphs (TM, Ma. Pilipczuk, P. Rzążewski, M. Sorge):
- Journal: SIAM Journal on Discrete Mathematics (SIDMA).
- Eurocomb 2021 (proceedings, presentation).
- ArXiv version.
- Also presented at TU Berlin seminar 2021 (presentation).
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Random 2-Cell Embeddings of Multistars (J. Campion Loth, K. Halasz, TM, B. Mohar, R. Šámal):
- Journal: Proceedings of the AMS.
- Eurocomb 2021 (proceedings).
- ArXiv version.
- The Phase Transition of Discrepancy in Random Hypergraphs (C. MacRury, TM, L. Pai, X. Pérez-Giménez):
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Note on 3-Coloring of (2P_4,C_5)-Free Graphs (V. Jelínek, T. Klimošová, TM, J. Novotná, A. Pokorná):
- Journal: Algorithmica.
- WG 2021 (Presentation, recording (25 mins)).
- ArXiv version.
-
On Weak Flexibility in Planar Graphs (B. Lidický, TM, K. Murphy, S. Zerbib):
- Journal: Graphs and Combinatorics.
- ArXiv version.
-
Flexible List Colorings in Graphs with Special Degeneracy Conditions (P. Bradshaw, TM, L. Stacho):
- Journal: Journal of Graph Theory.
- ISAAC 2020 (proceedings).
- ArXiv version.
- Also presented at SFU Discrete Math seminar 2021 (recording (50 mins) - P. Bradshaw).
- Also presented at University of Warsaw algorithms seminar 2021 (Presentation, recording (50 mins)).
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Clique-Width: Harnessing the Power of Atoms (K. Dabrowski, TM, J. Novotná, D. Paulusma, P. Rzążewski):
- Journal: Journal of Graph Theory.
- WG 2020 (proceedings).
- ArXiv version.
- Also presented at Haifa workshop 2020 (Presentation - J. Novotná).
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Flexibility of Planar Graphs – Sharpening the Tools to Get Lists of Size Four (I. Choi, F.C. Clemen, M. Ferrara, P. Horn, F. Ma, TM):
- Journal: Discrete Applied Mathematics.
- ArXiv version.
- Also presented at JMM 2020 (presentation).
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Optimal Discretization is Fixed-parameter Tractable (S. Kratsch, TM, I. Muzi, Ma. Pilipczuk, M. Sorge):
- SODA 2021 (proceedings).
- ArXiv version.
- Also presented at SFU Discrete Math seminar 2021 (Presentation, Recording (50 mins)).
- Also presented at Frontiers of Parameterized Complexity - Ma. Pilipczuk (Recording (70 mins)).
-
U-Bubble Model for Mixed Unit Interval Graphs and its Applications: The MaxCut Problem Revisited (J. Kratochvíl, TM, J. Novotná):
- Journal: Algorithmica.
- MFCS 2020 (proceedings, recording (20mins) - J. Novotná).
- ArXiv version.
- Approximation Algorithms for Steiner Tree Based on Star Contractions: A Unified View (R. Hušek, D. Knop, TM):
- Jones' Conjecture in subcubic graphs (M. Bonamy, F. Dross, TM, W. Nadara, Ma. Pilipczuk, Mi. Pilipczuk):
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FPT Algorithms for Diverse Collections of Hitting Sets (J. Baste, L. Jaffke, TM, G. Philip, G. Rote):
- Journal: Algorithms (Special Issue: New Frontiers in Parameterized Complexity and Algorithms).
- ArXiv version.
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Packing Directed Circuits Quarter- and Half-Integrally (TM, I. Muzi, Ma. Pilipczuk, P. Rzążewski, M. Sorge):
- Manuscript name: Packing Directed Circuits Quarter-Integrally.
- Journal: accepted to Combinatorica.
- ESA A 2019 (proceedings, presentation).
- ArXiv version.
- Presented also at the workshop Cycles and Colourings 2019.
- Presented also at Iowa State University seminar 2020 (recording (35mins)).
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Diversity of Solutions: An Exploration Through the Lens of Fixed-Parameter Tractability Theory (J. Baste, M.R. Fellows, L. Jaffke, TM, M. de Oliveira Oliveira, G. Philip, F.A. Rosamond):
- Manuscript name: Diversity in Combinatorial Optimization.
- Journal: Artificial Intelligence.
- IJCAI 2020 (proceedings, recording (5 mins),talk recording L. Jaffke (15 mins), poster).
- ArXiv version.
-
Flexibility of planar graphs without 4-cycles (TM): [PDF]
- Eurocomb 2019 (proceedings, presentation).
- ArXiv version.
- Presented also at DIMEA days 2019 (poster).
-
Flexibility of planar graphs of girth at least six (Z. Dvořák, TM, J. Musílek, O. Pangrác):
[PDF]
- Journal: Journal of Graph Theory.
- ArXiv version.
- Presented also at DIMEA days 2019 (poster).
-
Flexibility of triangle-free planar graphs (Z. Dvořák, TM, J. Musílek, O. Pangrác):
- Journal: Journal of Graph Theory.
- ArXiv version.
- Presented also at Cycles and Colourings 2017 (presentation) and DIMEA days 2019 (poster).
-
Steiner Tree Heuristics [PACE 2018 TRACK C] (R. Hušek, T. Toufar, D. Knop, TM, E. Eiben): [PDF]
- PACE report 2018
- Ceremony at IPEC announcing the results: We were awarded by 4th place in Track C.
- Public repository with our implementation.
- Ranking on public instances.
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Colouring (P_r+P_s)-Free Graphs (T. Klimošová, J. Malík, TM, J. Novotná, D. Paulusma, V. Slívová):
- Journal: Algorithmica.
- ISAAC 2018 (proceedings, presentation).
- ArXiv version.
- Also presented at ALGO seminar (presentation - J. Novotná) at the University of Bergen, May 2018; Noon lecture (presentation) at Charles University, Prague, December 2018.
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Parameterized Approximation Schemes for Steiner Trees with Small Number of Steiner Vertices (P. Dvořák, A.E. Feldmann, D. Knop, TM, T. Toufar, P. Veselý):
- Journal: SIAM Journal on Discrete Mathematics (SIDMA).
- STACS 2018 (proceedings, presentation).
- ArXiv version.
- Also presented at PAAW 2018, a workshop by ICALP conference (presentation); HALG 2018 (poster - P. Dvořák).
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On difference graphs and the local dimension of posets (J. Kim, R.R. Martin, TM, W. Shull, H.C. Smith, A. Uzzell, Z. Wang):
- Journal: European Journal of Combinatorics.
- ArXiv version.
- Also presented at Noon lecture at Charles University, Prague, May 2018; ALGO seminar (presentation) at the University of Bergen, Feb 2018; workshop HOMONOLO 2017.
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Notes on complexity of packing coloring (M. Kim, B. Lidický, TM, F. Pfender):
- Journal: Information Processing Letters.
- ArXiv version.
- Also presented at Warsaw University of Technology seminar;
- Cycles and Colourings 2018 (presentation).
-
Duality gap in interval linear programming (J. Novotná, M. Hladík, TM):
- Journal: Journal of Optimization Theory and Applications.
- SOR 2017(proceedings, presentation - J. Novotná).
- ArXiv version.
-
Parameterized Complexity of Fair Vertex Evaluation Problems (D. Knop, TM, T. Toufar): [PDF]
- Manuscript name: Parameterized complexity of fair deletion problems II.
- MFCS 2019 (proceedings, presentation - D. Knop).
- ArXiv version.
- Also presented at workshops CSGT 2017 (presentation, book of abstracts); MCGTC 2017; GROW 2017 (presentation); and at open problems session of ISAAC 2018 (presentation).
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Simplified Algorithmic Metatheorems Beyond MSO: Treewidth and Neighborhood Diversity (D. Knop, M. Koutecký, TM, T. Toufar):
- Journal: Logical Methods in Computer Science.
- WG 2017 - Best Student Paper Award ( proceedings, presentation - D. Knop).
- ArXiv version.
- Also presented at MCW XXII (2017).
-
Parameterized complexity of fair deletion problems (TM, T. Toufar):
- Journal: Discrete Applied Mathematics (Special issue).
- TAMC 2017 (proceedings, presentation - T. Toufar).
- ArXiv version.
- Also presented at BGW 2016 (presentation - T. Toufar); MEMICS 2016 (poster).
-
Anti-Path Cover on Sparse Graph Classes (P. Dvořák, D. Knop, TM):
- MEMICS 2016 (proceedings, presentation).
- ArXiv version.
- Also presented at BGW 2016 (presentation).
-
Triangle-free planar graphs with the smallest independence number (Z. Dvořak, TM, J. Musílek, O. Pangrác):
- Journal: Journal of Graph Theory.
- ArXiv version.
- Also presented at Cycles and Colourings 2016 (presentation - J. Musílek).
-
Computational complexity of Distance Edge labeling (D. Knop, TM):
- Journal: Discrete Applied Mathematics (Special issue).
- IWOCA 2015 (proceedings, presentation).
- ArXiv version.
- Also presented at Cycles and Colourings 2016 (presentation); Noon lecture at Charles University, Prague, 2015.
- A pre-printed version in ITI-series.
- Diploma Thesis: Výpočetní složitost problémů kombinatorické optimalizace pro specifické třídy grafů (in Czech) (2014).
Internships / Research Collaboration
- IT University of Copenhagen, Danemark, may 2023 (P. Lima)
- Postdoc University of Warsaw, Poland aug 2021 - feb 2022 (Mi. Pilipczuk, project BOBR)
- Postdoc Simon fraser University, Canada feb 2020 - aug 2021 (B. Mohar and L. Stacho)
- Iowa State University, USA jan 2020 (B. Lidický)
- Postdoc University of Warsaw, Poland oct 2019 - jan 2020 (Ma. Pilipczuk, project CUTACOMBS)
- Kansas University, USA jul 2019 (GRWC)
- University of Warsaw, Poland sep 2018 - sep 2019 (Ma. Pilipczuk, project CUTACOMBS)
- Durham University, UK nov 2018, apr-may 2019 (D. Paulusma)
- Warsaw University of Technology, Poland nov 2018
- University of Bergen, Norway jan-jul 2018 (Erasmus)
- LAMSADE, Université Paris-Dauphine, France dec 2017
- University of Denver, Colorado and University of Colorado Denver, USA jul 2017 (GRWC)
- DIMACS, Rutgers, The State University of New Jersey, US jun-jul 2015 (REU)
- Department of Computer and Information Science, University of Oregon, US apr 2015
- Grenoble Alpes University - Laboratory G-SCOP, France dec 2014
Organization
- ICALP 2018
- CSGT 2017
- Spring School 2014, 2016, 2017, 2018, 2019
- Homonolo 2015, 2016, 2017, 2018, 2019, 2021
Other (reports, ed.)
- Spring School 2018 printed in ITI-series.
- Czech-Slovak conference on Graph Theory 2017 printed in ITI-series.
- Spring School 2017 printed in ITI-series.
- Spring School 2016 printed in ITI-series.
- The report from REU 2015 printed in ITI-series.
PhD Thesis
- PhD Thesis 2019 at Charles University. [PDF]
- Extended astract of PhD Thesis at Charles University. [PDF]
masarik<a>mimuw.edu.pl
CENT building room 03.111, MIMUW, Banacha 2, Warsaw, 02-097, Poland
Room 1650, MIMUW, Banacha 2, Warsaw, 02-097, Poland
Room 8514, Department of Mathematics, Simon Fraser university, 8888 University Drive, Burnaby, V5A 1S6, Canada
Room 320, KAM MFF, Malostranské náměstí 25, Praha 1, 11800, Czech Republic