Participatory budgeting with project groups.

Krzysztof Sornat AGH University of Science and Technology, Krakow, Poland IDSIA (Dalle Molle Institute for Artificial Intelligence), Lugano, Switzerland https://home.agh.edu.pl/~pragma/#team https://scholar.google.com/citations?user=ZwLPLOYAAAAJ https://zbmath.org/authors/?q=ai:sornat.krzysztof https://orcid.org/0000-0001-7450-4269 https://www.wikidata.org/entity/Q115256567

Pallavi Jain 0001 Krzysztof Sornat Nimrod Talmon Meirav Zehavi Participatory budgeting with project groups. 103702 2026 156 J. Comput. Syst. Sci. https://doi.org/10.1016/j.jcss.2025.103702 db/journals/jcss/jcss156.html#JainSTZ26 streams/journals/jcss

Piotr Faliszewski Krzysztof Sornat Stanislaw Szufa Tomasz Was Diversity of Structured Domains via k-Kemeny Scores. 16880-16888 2026 AAAI https://doi.org/10.1609/aaai.v40i20.38733 conf/aaai/2026 db/conf/aaai/aaai2026.html#FaliszewskiSSW26 Alexandra Lassota Krzysztof Sornat Algorithms for Structured Elections Under Thiele Voting Rules. 17084-17092 2026 AAAI https://doi.org/10.1609/aaai.v40i20.38757 conf/aaai/2026 db/conf/aaai/aaai2026.html#LassotaS26

Piotr Faliszewski Lukasz Janeczko Dusan Knop Jan Pokorný 0001 Simon Schierreich Mateusz Sluszniak Krzysztof Sornat Participatory Budgeting Project Strength via Candidate Control. 2026 January abs/2601.16511 CoRR https://doi.org/10.48550/arXiv.2601.16511 db/journals/corr/corr2601.html#abs-2601-16511 streams/journals/corr

Piotr Faliszewski Piotr Skowron 0001 Arkadii Slinko Krzysztof Sornat Stanislaw Szufa Nimrod Talmon How Similar Are Two Elections? 2026 January abs/2601.19716 CoRR https://doi.org/10.48550/arXiv.2601.19716 db/journals/corr/corr2601.html#abs-2601-19716 streams/journals/corr

Piotr Faliszewski Krzysztof Sornat Stanislaw Szufa Tomasz Was Outer Diversity of Structured Domains. 2026 February abs/2602.15708 CoRR https://doi.org/10.48550/arXiv.2602.15708 db/journals/corr/corr2602.html#abs-2602-15708 streams/journals/corr

Pasin Manurangsi Krzysztof Sornat Polynomial-Time Algorithm for Thiele Voting Rules with Voter Interval Preferences. 2026 April abs/2604.05953 CoRR https://doi.org/10.48550/arXiv.2604.05953 db/journals/corr/corr2604.html#abs-2604-05953 streams/journals/corr

Piotr Faliszewski Jitka Mertlová Krzysztof Sornat Stanislaw Szufa Tomasz Was Agreement, Diversity, and Polarization Indices for Approval Elections. 2026 May abs/2605.14983 CoRR https://doi.org/10.48550/arXiv.2605.14983 db/journals/corr/corr2605.html#abs-2605-14983 streams/journals/corr

Piotr Faliszewski Piotr Skowron 0001 Arkadii Slinko Krzysztof Sornat Stanislaw Szufa Nimrod Talmon How similar are two elections? 103632 2025 150 J. Comput. Syst. Sci. https://doi.org/10.1016/j.jcss.2025.103632 db/journals/jcss/jcss150.html#FaliszewskiSSSST25 streams/journals/jcss

Piotr Faliszewski Lukasz Janeczko Dusan Knop Jan Pokorný 0001 Simon Schierreich Mateusz Sluszniak Krzysztof Sornat Participatory Budgeting Project Strength via Candidate Control. 2514-2516 2025 AAMAS https://dl.acm.org/doi/10.5555/3709347.3743921 conf/ifaamas/2025 db/conf/ifaamas/aamas2025.html#FaliszewskiJKPS25 Piotr Faliszewski Lukasz Janeczko Dusan Knop Jan Pokorný 0001 Simon Schierreich Mateusz Sluszniak Krzysztof Sornat Participatory Budgeting Project Strength via Candidate Control. 3821-3829 2025 IJCAI https://doi.org/10.24963/ijcai.2025/425 conf/ijcai/2025 db/conf/ijcai/ijcai2025.html#FaliszewskiJKPS25 Gregory Kehne Ulrike Schmidt-Kraepelin Krzysztof Sornat Robust Committee Voting, or The Other Side of Representation. 1131-1151 2025 EC https://doi.org/10.1145/3736252.3742676 conf/sigecom/2025 db/conf/sigecom/sigecom2025.html#KehneSS25

Gregory Kehne Ulrike Schmidt-Kraepelin Krzysztof Sornat Robust Committee Voting, or The Other Side of Representation. 2025 June abs/2506.18643 CoRR https://doi.org/10.48550/arXiv.2506.18643 db/journals/corr/corr2506.html#abs-2506-18643 streams/journals/corr

Piotr Faliszewski Krzysztof Sornat Stanislaw Szufa Tomasz Was Diversity of Structured Domains via k-Kemeny Scores. 2025 September abs/2509.15812 CoRR https://doi.org/10.48550/arXiv.2509.15812 db/journals/corr/corr2509.html#abs-2509-15812 streams/journals/corr

Piotr Faliszewski Krzysztof Sornat Stanislaw Szufa The Complexity of Subelection Isomorphism Problems. 1343-1371 2024 80 J. Artif. Intell. Res. https://doi.org/10.1613/jair.1.15550 https://www.wikidata.org/entity/Q130966466 db/journals/jair/jair80.html#FaliszewskiSS24 streams/journals/jair

Matthias Köppe Martin Koutecký Krzysztof Sornat Nimrod Talmon Fine-Grained Liquid Democracy for Cumulative Ballots. 1029-1037 2024 AAMAS https://dl.acm.org/doi/10.5555/3635637.3662958 conf/atal/2024 db/conf/atal/aamas2024.html#KoppeKST24 Fateme Abbasi Marek Adamczyk Miguel Bosch-Calvo Jaroslaw Byrka Fabrizio Grandoni 0001 Krzysztof Sornat Antoine Tinguely An O(loglog n)-Approximation for Submodular Facility Location. 5:1-5:20 2024 ICALP https://doi.org/10.4230/LIPIcs.ICALP.2024.5 conf/icalp/2024 db/conf/icalp/icalp2024.html#AbbasiABB0ST24 Alberto Del Pia Dusan Knop Alexandra Lassota Krzysztof Sornat Nimrod Talmon Aggregation of Continuous Preferences in One Dimension. 2748-2756 2024 IJCAI https://www.ijcai.org/proceedings/2024/304 conf/ijcai/2024 db/conf/ijcai/ijcai2024.html#PiaKLST24

Piotr Faliszewski Martin Lackner Krzysztof Sornat Stanislaw Szufa An Experimental Comparison of Multiwinner Voting Rules on Approval Elections. 2024 abs/2401.11870 CoRR https://doi.org/10.48550/arXiv.2401.11870 db/journals/corr/corr2401.html#abs-2401-11870

Piotr Faliszewski Martin Lackner Krzysztof Sornat Stanislaw Szufa An Experimental Comparison of Multiwinner Voting Rules on Approval Elections. 2675-2683 2023 IJCAI https://doi.org/10.24963/ijcai.2023/298 conf/ijcai/2023 db/conf/ijcai/ijcai2023.html#FaliszewskiLSS23 Piotr Faliszewski Andrzej Kaczmarczyk 0001 Krzysztof Sornat Stanislaw Szufa Tomasz Was Diversity, Agreement, and Polarization in Elections. 2684-2692 2023 IJCAI https://doi.org/10.24963/ijcai.2023/299 conf/ijcai/2023 db/conf/ijcai/ijcai2023.html#Faliszewski0SSW23

Piotr Faliszewski Andrzej Kaczmarczyk 0001 Krzysztof Sornat Stanislaw Szufa Tomasz Was Diversity, Agreement, and Polarization in Elections. 2023 abs/2305.09780 CoRR https://doi.org/10.48550/arXiv.2305.09780 db/journals/corr/corr2305.html#abs-2305-09780

Piotr Faliszewski Krzysztof Sornat Stanislaw Szufa The Complexity of Subelection Isomorphism Problems. 4991-4998 2022 AAAI https://doi.org/10.1609/aaai.v36i5.20430 conf/aaai/2022 db/conf/aaai/aaai2022.html#FaliszewskiSS22 Pallavi Jain 0001 Krzysztof Sornat Nimrod Talmon Preserving Consistency for Liquid Knapsack Voting. 221-238 2022 EUMAS https://doi.org/10.1007/978-3-031-20614-6_13 conf/eumas/2022 db/conf/eumas/eumas2022.html#JainST22 Krzysztof Sornat Virginia Vassilevska Williams Yinzhan Xu Near-Tight Algorithms for the Chamberlin-Courant and Thiele Voting Rules. 482-488 2022 IJCAI https://doi.org/10.24963/ijcai.2022/69 conf/ijcai/2022 db/conf/ijcai/ijcai2022.html#SornatWX22 Stanislaw Szufa Piotr Faliszewski Lukasz Janeczko Martin Lackner Arkadii Slinko Krzysztof Sornat Nimrod Talmon How to Sample Approval Elections? 496-502 2022 IJCAI https://doi.org/10.24963/ijcai.2022/71 conf/ijcai/2022 db/conf/ijcai/ijcai2022.html#SzufaFJLSST22

Stanislaw Szufa Piotr Faliszewski Lukasz Janeczko Martin Lackner Arkadii Slinko Krzysztof Sornat Nimrod Talmon How to Sample Approval Elections? 2022 abs/2207.01140 CoRR https://doi.org/10.48550/arXiv.2207.01140 db/journals/corr/corr2207.html#abs-2207-01140

Matthias Köppe Martin Koutecký Krzysztof Sornat Nimrod Talmon Fine-Grained Liquid Democracy for Cumulative Ballots. 2022 abs/2208.14441 CoRR https://doi.org/10.48550/arXiv.2208.14441 db/journals/corr/corr2208.html#abs-2208-14441

Fateme Abbasi Marek Adamczyk Miguel Bosch-Calvo Jaroslaw Byrka Fabrizio Grandoni 0001 Krzysztof Sornat Antoine Tinguely An O(loglog n)-Approximation for Submodular Facility Location. 2022 abs/2211.05474 CoRR https://doi.org/10.48550/arXiv.2211.05474 db/journals/corr/corr2211.html#abs-2211-05474

Krzysztof Sornat Virginia Vassilevska Williams Yinzhan Xu Near-Tight Algorithms for the Chamberlin-Courant and Thiele Voting Rules. 2022 abs/2212.14173 CoRR https://doi.org/10.48550/arXiv.2212.14173 db/journals/corr/corr2212.html#abs-2212-14173

Piotr Faliszewski Pasin Manurangsi Krzysztof Sornat Approximation and hardness of Shift-Bribery. 103520 2021 298 Artif. Intell. https://doi.org/10.1016/j.artint.2021.103520 db/journals/ai/ai298.html#FaliszewskiMS21

Waldo Gálvez Fabrizio Grandoni 0001 Afrouz Jabal Ameli Krzysztof Sornat On the Cycle Augmentation Problem: Hardness and Approximation Algorithms. 985-1008 2021 65 Theory Comput. Syst. 6 https://doi.org/10.1007/s00224-020-10025-6 db/journals/mst/mst65.html#GalvezGAS21

Georgios Amanatidis Peter Fulla Evangelos Markakis 0001 Krzysztof Sornat Inequity aversion pricing over social networks: Approximation algorithms and hardness results. 62-78 2021 871 Theor. Comput. Sci. https://doi.org/10.1016/j.tcs.2021.04.012 db/journals/tcs/tcs871.html#AmanatidisFMS21

Pallavi Jain 0001 Krzysztof Sornat Nimrod Talmon Preserving Consistency for Liquid Knapsack Voting. 1542-1544 2021 AAMAS https://www.ifaamas.org/Proceedings/aamas2021/pdfs/p1542.pdf https://dl.acm.org/doi/10.5555/3463952.3464153 conf/atal/2021 db/conf/atal/aamas2021.html#0001ST21 Pallavi Jain 0001 Krzysztof Sornat Nimrod Talmon Meirav Zehavi Participatory Budgeting with Project Groups. 276-282 2021 IJCAI https://doi.org/10.24963/ijcai.2021/39 conf/ijcai/2021 db/conf/ijcai/ijcai2021.html#0001STZ21 Krzysztof Sornat Virginia Vassilevska Williams Yinzhan Xu Fine-Grained Complexity and Algorithms for the Schulze Voting Method. 841-859 2021 EC https://doi.org/10.1145/3465456.3467630 conf/sigecom/2021 db/conf/sigecom/sigecom2021.html#SornatWX21

Krzysztof Sornat Virginia Vassilevska Williams Yinzhan Xu Fine-Grained Complexity and Algorithms for the Schulze Voting Method. 2021 abs/2103.03959 CoRR https://arxiv.org/abs/2103.03959 db/journals/corr/corr2103.html#abs-2103-03959

Szymon Dudycz Pasin Manurangsi Jan Marcinkowski Krzysztof Sornat Tight Approximation for Proportional Approval Voting. 276-282 2020 IJCAI https://doi.org/10.24963/ijcai.2020/39 conf/ijcai/2020 db/conf/ijcai/ijcai2020.html#DudyczMMS20 Pallavi Jain 0001 Krzysztof Sornat Nimrod Talmon Participatory Budgeting with Project Interactions. 386-392 2020 IJCAI https://doi.org/10.24963/ijcai.2020/54 conf/ijcai/2020 db/conf/ijcai/ijcai2020.html#0001ST20

Pallavi Jain 0001 Krzysztof Sornat Nimrod Talmon Meirav Zehavi Participatory Budgeting with Project Groups. 2020 abs/2012.05213 CoRR https://arxiv.org/abs/2012.05213 db/journals/corr/corr2012.html#abs-2012-05213

Piotr Faliszewski Pasin Manurangsi Krzysztof Sornat Approximation and Hardness of Shift-Bribery. 1901-1908 2019 AAAI https://doi.org/10.1609/aaai.v33i01.33011901 conf/aaai/2019 db/conf/aaai/aaai2019.html#FaliszewskiMS19 Waldo Gálvez Fabrizio Grandoni 0001 Afrouz Jabal Ameli Krzysztof Sornat On the Cycle Augmentation Problem: Hardness and Approximation Algorithms. 138-153 2019 WAOA https://doi.org/10.1007/978-3-030-39479-0_10 conf/waoa/2019 db/conf/waoa/waoa2019.html#Galvez0AS19

Piotr Faliszewski Pasin Manurangsi Krzysztof Sornat Approximation and Hardness of Shift-Bribery. 2019 abs/1908.10562 CoRR http://arxiv.org/abs/1908.10562 db/journals/corr/corr1908.html#abs-1908-10562

Marek Cygan Lukasz Kowalik Arkadiusz Socala Krzysztof Sornat Approximation and Parameterized Complexity of Minimax Approval Voting. 495-513 2018 63 J. Artif. Intell. Res. https://doi.org/10.1613/jair.1.11253 https://www.wikidata.org/entity/Q128873806 db/journals/jair/jair63.html#CyganKSS18

Jaroslaw Byrka Piotr Skowron 0001 Krzysztof Sornat Proportional Approval Voting, Harmonic k-median, and Negative Association. 26:1-26:14 2018 ICALP https://doi.org/10.4230/LIPIcs.ICALP.2018.26 conf/icalp/2018 db/conf/icalp/icalp2018.html#ByrkaSS18 Jaroslaw Byrka Krzysztof Sornat Joachim Spoerhase Constant-factor approximation for ordered k-median. 620-631 2018 STOC https://doi.org/10.1145/3188745.3188930 conf/stoc/2018 db/conf/stoc/stoc2018.html#ByrkaSS18 Marek Cygan Lukasz Kowalik Arkadiusz Socala Krzysztof Sornat Approximation and Parameterized Complexity of Minimax Approval Voting. 459-465 2017 AAAI https://doi.org/10.1609/aaai.v31i1.10575 conf/aaai/2017 db/conf/aaai/aaai2017.html#CyganKSS17

Jaroslaw Byrka Piotr Skowron 0001 Krzysztof Sornat Proportional Approval Voting, Harmonic k-median, and Negative Association. 2017 abs/1704.02183 CoRR http://arxiv.org/abs/1704.02183 db/journals/corr/corr1704.html#ByrkaSS17

Jaroslaw Byrka Krzysztof Sornat Joachim Spoerhase Constant-Factor Approximation for Ordered k-Median. 2017 abs/1711.01972 CoRR http://arxiv.org/abs/1711.01972 db/journals/corr/corr1711.html#abs-1711-01972

Georgios Amanatidis Evangelos Markakis 0001 Krzysztof Sornat Inequity Aversion Pricing over Social Networks: Approximation Algorithms and Hardness Results. 9:1-9:13 2016 MFCS https://doi.org/10.4230/LIPIcs.MFCS.2016.9 conf/mfcs/2016 db/conf/mfcs/mfcs2016.html#AmanatidisMS16

Georgios Amanatidis Evangelos Markakis 0001 Krzysztof Sornat Inequity Aversion Pricing over Social Networks: Approximation Algorithms and Hardness Results. 2016 abs/1606.06664 CoRR http://arxiv.org/abs/1606.06664 db/journals/corr/corr1606.html#AmanatidisMS16

Marek Cygan Lukasz Kowalik Arkadiusz Socala Krzysztof Sornat Approximation and Parameterized Complexity of Minimax Approval Voting. 2016 abs/1607.07906 CoRR http://arxiv.org/abs/1607.07906 db/journals/corr/corr1607.html#CyganKSS16

Jaroslaw Byrka Krzysztof Sornat PTAS for Minimax Approval Voting. 203-217 2014 WINE https://doi.org/10.1007/978-3-319-13129-0_15 conf/wine/2014 db/conf/wine/wine2014.html#ByrkaS14

Jaroslaw Byrka Krzysztof Sornat PTAS for Minimax Approval Voting. 2014 abs/1407.7216 CoRR http://arxiv.org/abs/1407.7216 db/journals/corr/corr1407.html#ByrkaS14

Fateme Abbasi Marek Adamczyk Georgios Amanatidis Afrouz Jabal Ameli Jaroslaw Byrka Miguel Bosch CalvoMiguel Bosch-Calvo Marek Cygan Szymon Dudycz Piotr Faliszewski Peter Fulla Waldo Gálvez Fabrizio Grandoni 0001 Pallavi Jain 0001 Lukasz Janeczko Andrzej Kaczmarczyk 0001 Gregory Kehne Dusan Knop Matthias Köppe Martin Koutecký Lukasz Kowalik Martin Lackner Alexandra Lassota Pasin Manurangsi Jan Marcinkowski Evangelos Markakis 0001 Jitka Mertlová Alberto Del Pia Jan Pokorný 0001 Simon Schierreich Ulrike Schmidt-Kraepelin Piotr Skowron 0001 Arkadii M. SlinkoArkadii Slinko Mateusz Sluszniak Arkadiusz Socala Joachim Spoerhase Stanislaw Szufa Nimrod Talmon Antoine Tinguely Tomasz Was Virginia Vassilevska Williams Yinzhan Xu Meirav Zehavi