[{"_id":"14417","conference":{"name":"MFCS: Symposium on Mathematical Foundations of Computer Science","start_date":"2023-08-28","end_date":"2023-09-01","location":"Bordeaux, France"},"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"type":"conference","status":"public","date_updated":"2023-10-09T09:22:37Z","ddc":["000"],"file_date_updated":"2023-10-09T09:19:11Z","department":[{"_id":"KrCh"}],"abstract":[{"text":"Entropic risk (ERisk) is an established risk measure in finance, quantifying risk by an exponential re-weighting of rewards. We study ERisk for the first time in the context of turn-based stochastic games with the total reward objective. This gives rise to an objective function that demands the control of systems in a risk-averse manner. We show that the resulting games are determined and, in particular, admit optimal memoryless deterministic strategies. This contrasts risk measures that previously have been considered in the special case of Markov decision processes and that require randomization and/or memory. We provide several results on the decidability and the computational complexity of the threshold problem, i.e. whether the optimal value of ERisk exceeds a given threshold. In the most general case, the problem is decidable subject to Shanuel’s conjecture. If all inputs are rational, the resulting threshold problem can be solved using algebraic numbers, leading to decidability via a polynomial-time reduction to the existential theory of the reals. Further restrictions on the encoding of the input allow the solution of the threshold problem in NP∩coNP. Finally, an approximation algorithm for the optimal value of ERisk is provided.","lang":"eng"}],"oa_version":"Published Version","alternative_title":["LIPIcs"],"scopus_import":"1","intvolume":" 272","month":"08","publication_status":"published","publication_identifier":{"isbn":["9783959772921"],"eissn":["1868-8969"]},"language":[{"iso":"eng"}],"file":[{"content_type":"application/pdf","access_level":"open_access","relation":"main_file","checksum":"402281b17ed669bbf149d0fdf68ac201","file_id":"14418","success":1,"date_updated":"2023-10-09T09:19:11Z","file_size":826843,"creator":"dernst","date_created":"2023-10-09T09:19:11Z","file_name":"2023_LIPIcsMFCS_Baier.pdf"}],"license":"https://creativecommons.org/licenses/by/4.0/","ec_funded":1,"volume":272,"article_number":"15","project":[{"_id":"0599E47C-7A3F-11EA-A408-12923DDC885E","call_identifier":"H2020","name":"Formal Methods for Stochastic Models: Algorithms and Applications","grant_number":"863818"}],"citation":{"mla":"Baier, Christel, et al. “Entropic Risk for Turn-Based Stochastic Games.” 48th International Symposium on Mathematical Foundations of Computer Science, vol. 272, 15, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023, doi:10.4230/LIPIcs.MFCS.2023.15.","ama":"Baier C, Chatterjee K, Meggendorfer T, Piribauer J. Entropic risk for turn-based stochastic games. In: 48th International Symposium on Mathematical Foundations of Computer Science. Vol 272. Schloss Dagstuhl - Leibniz-Zentrum für Informatik; 2023. doi:10.4230/LIPIcs.MFCS.2023.15","apa":"Baier, C., Chatterjee, K., Meggendorfer, T., & Piribauer, J. (2023). Entropic risk for turn-based stochastic games. In 48th International Symposium on Mathematical Foundations of Computer Science (Vol. 272). Bordeaux, France: Schloss Dagstuhl - Leibniz-Zentrum für Informatik. https://doi.org/10.4230/LIPIcs.MFCS.2023.15","ieee":"C. Baier, K. Chatterjee, T. Meggendorfer, and J. Piribauer, “Entropic risk for turn-based stochastic games,” in 48th International Symposium on Mathematical Foundations of Computer Science, Bordeaux, France, 2023, vol. 272.","short":"C. Baier, K. Chatterjee, T. Meggendorfer, J. Piribauer, in:, 48th International Symposium on Mathematical Foundations of Computer Science, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023.","chicago":"Baier, Christel, Krishnendu Chatterjee, Tobias Meggendorfer, and Jakob Piribauer. “Entropic Risk for Turn-Based Stochastic Games.” In 48th International Symposium on Mathematical Foundations of Computer Science, Vol. 272. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023. https://doi.org/10.4230/LIPIcs.MFCS.2023.15.","ista":"Baier C, Chatterjee K, Meggendorfer T, Piribauer J. 2023. Entropic risk for turn-based stochastic games. 48th International Symposium on Mathematical Foundations of Computer Science. MFCS: Symposium on Mathematical Foundations of Computer Science, LIPIcs, vol. 272, 15."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","external_id":{"arxiv":["2307.06611"]},"article_processing_charge":"Yes","author":[{"first_name":"Christel","full_name":"Baier, Christel","last_name":"Baier"},{"orcid":"0000-0002-4561-241X","full_name":"Chatterjee, Krishnendu","last_name":"Chatterjee","id":"2E5DCA20-F248-11E8-B48F-1D18A9856A87","first_name":"Krishnendu"},{"id":"b21b0c15-30a2-11eb-80dc-f13ca25802e1","first_name":"Tobias","orcid":"0000-0002-1712-2165","full_name":"Meggendorfer, Tobias","last_name":"Meggendorfer"},{"first_name":"Jakob","full_name":"Piribauer, Jakob","last_name":"Piribauer"}],"title":"Entropic risk for turn-based stochastic games","acknowledgement":"This work was partly funded by the ERC CoG 863818 (ForM-SMArt), the DFG Grant\r\n389792660 as part of TRR 248 (Foundations of Perspicuous Software Systems), the Cluster of\r\nExcellence EXC 2050/1 (CeTI, project ID 390696704, as part of Germany’s Excellence Strategy), and the DFG projects BA-1679/11-1 and BA-1679/12-1.","oa":1,"publisher":"Schloss Dagstuhl - Leibniz-Zentrum für Informatik","quality_controlled":"1","year":"2023","has_accepted_license":"1","publication":"48th International Symposium on Mathematical Foundations of Computer Science","day":"21","date_created":"2023-10-09T09:21:05Z","doi":"10.4230/LIPIcs.MFCS.2023.15","date_published":"2023-08-21T00:00:00Z"},{"external_id":{"pmid":["36848357"],"isi":["000996122900022"]},"article_processing_charge":"No","author":[{"first_name":"Jody C.","full_name":"Mckerral, Jody C.","last_name":"Mckerral"},{"full_name":"Kleshnina, Maria","last_name":"Kleshnina","id":"4E21749C-F248-11E8-B48F-1D18A9856A87","first_name":"Maria"},{"last_name":"Ejov","full_name":"Ejov, Vladimir","first_name":"Vladimir"},{"first_name":"Louise","last_name":"Bartle","full_name":"Bartle, Louise"},{"first_name":"James G.","full_name":"Mitchell, James G.","last_name":"Mitchell"},{"first_name":"Jerzy A.","full_name":"Filar, Jerzy A.","last_name":"Filar"}],"title":"Empirical parameterisation and dynamical analysis of the allometric Rosenzweig-MacArthur equations","citation":{"mla":"Mckerral, Jody C., et al. “Empirical Parameterisation and Dynamical Analysis of the Allometric Rosenzweig-MacArthur Equations.” PLoS One, vol. 18, no. 2, Public Library of Science, 2023, p. e0279838, doi:10.1371/journal.pone.0279838.","ieee":"J. C. Mckerral, M. Kleshnina, V. Ejov, L. Bartle, J. G. Mitchell, and J. A. Filar, “Empirical parameterisation and dynamical analysis of the allometric Rosenzweig-MacArthur equations,” PLoS One, vol. 18, no. 2. Public Library of Science, p. e0279838, 2023.","short":"J.C. Mckerral, M. Kleshnina, V. Ejov, L. Bartle, J.G. Mitchell, J.A. Filar, PLoS One 18 (2023) e0279838.","apa":"Mckerral, J. C., Kleshnina, M., Ejov, V., Bartle, L., Mitchell, J. G., & Filar, J. A. (2023). Empirical parameterisation and dynamical analysis of the allometric Rosenzweig-MacArthur equations. PLoS One. Public Library of Science. https://doi.org/10.1371/journal.pone.0279838","ama":"Mckerral JC, Kleshnina M, Ejov V, Bartle L, Mitchell JG, Filar JA. Empirical parameterisation and dynamical analysis of the allometric Rosenzweig-MacArthur equations. PLoS One. 2023;18(2):e0279838. doi:10.1371/journal.pone.0279838","chicago":"Mckerral, Jody C., Maria Kleshnina, Vladimir Ejov, Louise Bartle, James G. Mitchell, and Jerzy A. Filar. “Empirical Parameterisation and Dynamical Analysis of the Allometric Rosenzweig-MacArthur Equations.” PLoS One. Public Library of Science, 2023. https://doi.org/10.1371/journal.pone.0279838.","ista":"Mckerral JC, Kleshnina M, Ejov V, Bartle L, Mitchell JG, Filar JA. 2023. Empirical parameterisation and dynamical analysis of the allometric Rosenzweig-MacArthur equations. PLoS One. 18(2), e0279838."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","page":"e0279838","date_created":"2023-03-05T23:01:05Z","date_published":"2023-02-27T00:00:00Z","doi":"10.1371/journal.pone.0279838","year":"2023","isi":1,"has_accepted_license":"1","publication":"PLoS One","day":"27","oa":1,"publisher":"Public Library of Science","quality_controlled":"1","acknowledgement":"This research was supported by an Australian Government Research Training Program\r\n(RTP) Scholarship to JCM (https://www.dese.gov.au), and LB is supported by the Centre de\r\nrecherche sur le vieillissement Fellowship Program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.","department":[{"_id":"KrCh"}],"file_date_updated":"2023-03-07T10:26:45Z","date_updated":"2023-10-17T12:53:30Z","ddc":["000"],"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"article_type":"original","type":"journal_article","status":"public","_id":"12706","volume":18,"issue":"2","publication_status":"published","publication_identifier":{"eissn":["1932-6203"]},"language":[{"iso":"eng"}],"file":[{"creator":"cchlebak","date_updated":"2023-03-07T10:26:45Z","file_size":1257003,"date_created":"2023-03-07T10:26:45Z","file_name":"2023_PLOSOne_Mckerral.pdf","access_level":"open_access","relation":"main_file","content_type":"application/pdf","checksum":"798ed5739a4117b03173e5d56e0534c9","file_id":"12712","success":1}],"scopus_import":"1","intvolume":" 18","month":"02","abstract":[{"text":"Allometric settings of population dynamics models are appealing due to their parsimonious nature and broad utility when studying system level effects. Here, we parameterise the size-scaled Rosenzweig-MacArthur differential equations to eliminate prey-mass dependency, facilitating an in depth analytic study of the equations which incorporates scaling parameters’ contributions to coexistence. We define the functional response term to match empirical findings, and examine situations where metabolic theory derivations and observation diverge. The dynamical properties of the Rosenzweig-MacArthur system, encompassing the distribution of size-abundance equilibria, the scaling of period and amplitude of population cycling, and relationships between predator and prey abundances, are consistent with empirical observation. Our parameterisation is an accurate minimal model across 15+ orders of mass magnitude.","lang":"eng"}],"pmid":1,"oa_version":"Published Version"},{"abstract":[{"text":"We consider bidding games, a class of two-player zero-sum graph games. The game proceeds as follows. Both players have bounded budgets. A token is placed on a vertex of a graph, in each turn the players simultaneously submit bids, and the higher bidder moves the token, where we break bidding ties in favor of Player 1. Player 1 wins the game iff the token visits a designated target vertex. We consider, for the first time, poorman discrete-bidding in which the granularity of the bids is restricted and the higher bid is paid to the bank. Previous work either did not impose granularity restrictions or considered Richman bidding (bids are paid to the opponent). While the latter mechanisms are technically more accessible, the former is more appealing from a practical standpoint. Our study focuses on threshold budgets, which is the necessary and sufficient initial budget required for Player 1 to ensure winning against a given Player 2 budget. We first show existence of thresholds. In DAGs, we show that threshold budgets can be approximated with error bounds by thresholds under continuous-bidding and that they exhibit a periodic behavior. We identify closed-form solutions in special cases. We implement and experiment with an algorithm to find threshold budgets.","lang":"eng"}],"oa_version":"Published Version","scopus_import":"1","month":"09","intvolume":" 372","publication_identifier":{"issn":["0922-6389"],"isbn":["9781643684369"]},"publication_status":"published","file":[{"date_created":"2023-11-13T10:16:10Z","file_name":"2023_FAIA_Avni.pdf","date_updated":"2023-11-13T10:16:10Z","file_size":501011,"creator":"dernst","checksum":"1390ca38480fa4cf286b0f1a42e8c12f","file_id":"14529","success":1,"content_type":"application/pdf","access_level":"open_access","relation":"main_file"}],"language":[{"iso":"eng"}],"volume":372,"license":"https://creativecommons.org/licenses/by-nc/4.0/","ec_funded":1,"_id":"14518","type":"conference","conference":{"name":"ECAI: European Conference on Artificial Intelligence","start_date":"2023-09-30","end_date":"2023-10-04","location":"Krakow, Poland"},"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc/4.0/legalcode","image":"/images/cc_by_nc.png","name":"Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)","short":"CC BY-NC (4.0)"},"status":"public","date_updated":"2023-11-13T10:18:45Z","ddc":["000"],"department":[{"_id":"ToHe"},{"_id":"KrCh"}],"file_date_updated":"2023-11-13T10:16:10Z","acknowledgement":"This research was supported in part by ISF grant no. 1679/21, ERC CoG 863818 (FoRM-SMArt) and the European Union’s Horizon 2020 research and innovation programme under the Marie SkłodowskaCurie Grant Agreement No. 665385.","quality_controlled":"1","publisher":"IOS Press","oa":1,"has_accepted_license":"1","year":"2023","day":"28","publication":"Frontiers in Artificial Intelligence and Applications","page":"141-148","date_published":"2023-09-28T00:00:00Z","doi":"10.3233/FAIA230264","date_created":"2023-11-12T23:00:56Z","project":[{"name":"International IST Doctoral Program","grant_number":"665385","_id":"2564DBCA-B435-11E9-9278-68D0E5697425","call_identifier":"H2020"},{"call_identifier":"H2020","_id":"0599E47C-7A3F-11EA-A408-12923DDC885E","name":"Formal Methods for Stochastic Models: Algorithms and Applications","grant_number":"863818"}],"citation":{"ista":"Avni G, Meggendorfer T, Sadhukhan S, Tkadlec J, Zikelic D. 2023. Reachability poorman discrete-bidding games. Frontiers in Artificial Intelligence and Applications. ECAI: European Conference on Artificial Intelligence vol. 372, 141–148.","chicago":"Avni, Guy, Tobias Meggendorfer, Suman Sadhukhan, Josef Tkadlec, and Dorde Zikelic. “Reachability Poorman Discrete-Bidding Games.” In Frontiers in Artificial Intelligence and Applications, 372:141–48. IOS Press, 2023. https://doi.org/10.3233/FAIA230264.","ieee":"G. Avni, T. Meggendorfer, S. Sadhukhan, J. Tkadlec, and D. Zikelic, “Reachability poorman discrete-bidding games,” in Frontiers in Artificial Intelligence and Applications, Krakow, Poland, 2023, vol. 372, pp. 141–148.","short":"G. Avni, T. Meggendorfer, S. Sadhukhan, J. Tkadlec, D. Zikelic, in:, Frontiers in Artificial Intelligence and Applications, IOS Press, 2023, pp. 141–148.","ama":"Avni G, Meggendorfer T, Sadhukhan S, Tkadlec J, Zikelic D. Reachability poorman discrete-bidding games. In: Frontiers in Artificial Intelligence and Applications. Vol 372. IOS Press; 2023:141-148. doi:10.3233/FAIA230264","apa":"Avni, G., Meggendorfer, T., Sadhukhan, S., Tkadlec, J., & Zikelic, D. (2023). Reachability poorman discrete-bidding games. In Frontiers in Artificial Intelligence and Applications (Vol. 372, pp. 141–148). Krakow, Poland: IOS Press. https://doi.org/10.3233/FAIA230264","mla":"Avni, Guy, et al. “Reachability Poorman Discrete-Bidding Games.” Frontiers in Artificial Intelligence and Applications, vol. 372, IOS Press, 2023, pp. 141–48, doi:10.3233/FAIA230264."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","author":[{"full_name":"Avni, Guy","orcid":"0000-0001-5588-8287","last_name":"Avni","first_name":"Guy","id":"463C8BC2-F248-11E8-B48F-1D18A9856A87"},{"full_name":"Meggendorfer, Tobias","orcid":"0000-0002-1712-2165","last_name":"Meggendorfer","first_name":"Tobias","id":"b21b0c15-30a2-11eb-80dc-f13ca25802e1"},{"last_name":"Sadhukhan","full_name":"Sadhukhan, Suman","first_name":"Suman"},{"id":"3F24CCC8-F248-11E8-B48F-1D18A9856A87","first_name":"Josef","full_name":"Tkadlec, Josef","orcid":"0000-0002-1097-9684","last_name":"Tkadlec"},{"first_name":"Dorde","id":"294AA7A6-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-4681-1699","full_name":"Zikelic, Dorde","last_name":"Zikelic"}],"article_processing_charge":"No","external_id":{"arxiv":["2307.15218"]},"title":"Reachability poorman discrete-bidding games"},{"citation":{"apa":"Ansaripour, M., Chatterjee, K., Henzinger, T. A., Lechner, M., & Zikelic, D. (2023). Learning provably stabilizing neural controllers for discrete-time stochastic systems. In 21st International Symposium on Automated Technology for Verification and Analysis (Vol. 14215, pp. 357–379). Singapore, Singapore: Springer Nature. https://doi.org/10.1007/978-3-031-45329-8_17","ama":"Ansaripour M, Chatterjee K, Henzinger TA, Lechner M, Zikelic D. Learning provably stabilizing neural controllers for discrete-time stochastic systems. In: 21st International Symposium on Automated Technology for Verification and Analysis. Vol 14215. Springer Nature; 2023:357-379. doi:10.1007/978-3-031-45329-8_17","short":"M. Ansaripour, K. Chatterjee, T.A. Henzinger, M. Lechner, D. Zikelic, in:, 21st International Symposium on Automated Technology for Verification and Analysis, Springer Nature, 2023, pp. 357–379.","ieee":"M. Ansaripour, K. Chatterjee, T. A. Henzinger, M. Lechner, and D. Zikelic, “Learning provably stabilizing neural controllers for discrete-time stochastic systems,” in 21st International Symposium on Automated Technology for Verification and Analysis, Singapore, Singapore, 2023, vol. 14215, pp. 357–379.","mla":"Ansaripour, Matin, et al. “Learning Provably Stabilizing Neural Controllers for Discrete-Time Stochastic Systems.” 21st International Symposium on Automated Technology for Verification and Analysis, vol. 14215, Springer Nature, 2023, pp. 357–79, doi:10.1007/978-3-031-45329-8_17.","ista":"Ansaripour M, Chatterjee K, Henzinger TA, Lechner M, Zikelic D. 2023. Learning provably stabilizing neural controllers for discrete-time stochastic systems. 21st International Symposium on Automated Technology for Verification and Analysis. ATVA: Automated Technology for Verification and Analysis, LNCS, vol. 14215, 357–379.","chicago":"Ansaripour, Matin, Krishnendu Chatterjee, Thomas A Henzinger, Mathias Lechner, and Dorde Zikelic. “Learning Provably Stabilizing Neural Controllers for Discrete-Time Stochastic Systems.” In 21st International Symposium on Automated Technology for Verification and Analysis, 14215:357–79. Springer Nature, 2023. https://doi.org/10.1007/978-3-031-45329-8_17."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_processing_charge":"No","author":[{"first_name":"Matin","last_name":"Ansaripour","full_name":"Ansaripour, Matin"},{"orcid":"0000-0002-4561-241X","full_name":"Chatterjee, Krishnendu","last_name":"Chatterjee","first_name":"Krishnendu","id":"2E5DCA20-F248-11E8-B48F-1D18A9856A87"},{"id":"40876CD8-F248-11E8-B48F-1D18A9856A87","first_name":"Thomas A","last_name":"Henzinger","full_name":"Henzinger, Thomas A","orcid":"0000-0002-2985-7724"},{"full_name":"Lechner, Mathias","last_name":"Lechner","id":"3DC22916-F248-11E8-B48F-1D18A9856A87","first_name":"Mathias"},{"first_name":"Dorde","id":"294AA7A6-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-4681-1699","full_name":"Zikelic, Dorde","last_name":"Zikelic"}],"title":"Learning provably stabilizing neural controllers for discrete-time stochastic systems","project":[{"_id":"62781420-2b32-11ec-9570-8d9b63373d4d","call_identifier":"H2020","name":"Vigilant Algorithmic Monitoring of Software","grant_number":"101020093"},{"name":"Formal Methods for Stochastic Models: Algorithms and Applications","grant_number":"863818","call_identifier":"H2020","_id":"0599E47C-7A3F-11EA-A408-12923DDC885E"},{"call_identifier":"H2020","_id":"2564DBCA-B435-11E9-9278-68D0E5697425","grant_number":"665385","name":"International IST Doctoral Program"}],"year":"2023","publication":"21st International Symposium on Automated Technology for Verification and Analysis","day":"22","page":"357-379","date_created":"2023-11-19T23:00:56Z","date_published":"2023-10-22T00:00:00Z","doi":"10.1007/978-3-031-45329-8_17","acknowledgement":"This work was supported in part by the ERC-2020-AdG 101020093, ERC CoG 863818 (FoRM-SMArt) and the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 665385.","quality_controlled":"1","publisher":"Springer Nature","date_updated":"2023-11-20T08:30:20Z","department":[{"_id":"ToHe"},{"_id":"KrCh"}],"_id":"14559","conference":{"name":"ATVA: Automated Technology for Verification and Analysis","start_date":"2023-10-24","location":"Singapore, Singapore","end_date":"2023-10-27"},"type":"conference","status":"public","publication_status":"published","publication_identifier":{"eissn":["1611-3349"],"isbn":["9783031453281"],"issn":["0302-9743"]},"language":[{"iso":"eng"}],"ec_funded":1,"volume":14215,"abstract":[{"text":"We consider the problem of learning control policies in discrete-time stochastic systems which guarantee that the system stabilizes within some specified stabilization region with probability 1. Our approach is based on the novel notion of stabilizing ranking supermartingales (sRSMs) that we introduce in this work. Our sRSMs overcome the limitation of methods proposed in previous works whose applicability is restricted to systems in which the stabilizing region cannot be left once entered under any control policy. We present a learning procedure that learns a control policy together with an sRSM that formally certifies probability 1 stability, both learned as neural networks. We show that this procedure can also be adapted to formally verifying that, under a given Lipschitz continuous control policy, the stochastic system stabilizes within some stabilizing region with probability 1. Our experimental evaluation shows that our learning procedure can successfully learn provably stabilizing policies in practice.","lang":"eng"}],"oa_version":"None","scopus_import":"1","alternative_title":["LNCS"],"intvolume":" 14215","month":"10"},{"_id":"13238","type":"conference","conference":{"start_date":"2023-06-06","end_date":"2023-06-09","location":"Alcala de Henares, Spain","name":"SIROCCO: Structural Information and Communication Complexity"},"status":"public","date_updated":"2023-11-30T10:54:51Z","department":[{"_id":"KrPi"},{"_id":"KrCh"}],"abstract":[{"text":"We consider a natural problem dealing with weighted packet selection across a rechargeable link, which e.g., finds applications in cryptocurrency networks. The capacity of a link (u, v) is determined by how much nodes u and v allocate for this link. Specifically, the input is a finite ordered sequence of packets that arrive in both directions along a link. Given (u, v) and a packet of weight x going from u to v, node u can either accept or reject the packet. If u accepts the packet, the capacity on link (u, v) decreases by x. Correspondingly, v’s capacity on (u, v) increases by x. If a node rejects the packet, this will entail a cost affinely linear in the weight of the packet. A link is “rechargeable” in the sense that the total capacity of the link has to remain constant, but the allocation of capacity at the ends of the link can depend arbitrarily on the nodes’ decisions. The goal is to minimise the sum of the capacity injected into the link and the cost of rejecting packets. We show that the problem is NP-hard, but can be approximated efficiently with a ratio of (1+ε)⋅(1+3–√) for some arbitrary ε>0.\r\n.","lang":"eng"}],"oa_version":"Preprint","scopus_import":"1","alternative_title":["LNCS"],"main_file_link":[{"url":"https://doi.org/10.48550/arXiv.2204.13459","open_access":"1"}],"month":"05","intvolume":" 13892","publication_identifier":{"isbn":["9783031327322"],"eissn":["1611-3349"],"issn":["0302-9743"]},"publication_status":"published","language":[{"iso":"eng"}],"related_material":{"record":[{"id":"14506","status":"public","relation":"dissertation_contains"}]},"volume":13892,"ec_funded":1,"project":[{"_id":"0599E47C-7A3F-11EA-A408-12923DDC885E","call_identifier":"H2020","name":"Formal Methods for Stochastic Models: Algorithms and Applications","grant_number":"863818"}],"citation":{"chicago":"Schmid, Stefan, Jakub Svoboda, and Michelle X Yeo. “Weighted Packet Selection for Rechargeable Links in Cryptocurrency Networks: Complexity and Approximation.” In SIROCCO 2023: Structural Information and Communication Complexity , 13892:576–94. Springer Nature, 2023. https://doi.org/10.1007/978-3-031-32733-9_26.","ista":"Schmid S, Svoboda J, Yeo MX. 2023. Weighted packet selection for rechargeable links in cryptocurrency networks: Complexity and approximation. SIROCCO 2023: Structural Information and Communication Complexity . SIROCCO: Structural Information and Communication Complexity, LNCS, vol. 13892, 576–594.","mla":"Schmid, Stefan, et al. “Weighted Packet Selection for Rechargeable Links in Cryptocurrency Networks: Complexity and Approximation.” SIROCCO 2023: Structural Information and Communication Complexity , vol. 13892, Springer Nature, 2023, pp. 576–94, doi:10.1007/978-3-031-32733-9_26.","apa":"Schmid, S., Svoboda, J., & Yeo, M. X. (2023). Weighted packet selection for rechargeable links in cryptocurrency networks: Complexity and approximation. In SIROCCO 2023: Structural Information and Communication Complexity (Vol. 13892, pp. 576–594). Alcala de Henares, Spain: Springer Nature. https://doi.org/10.1007/978-3-031-32733-9_26","ama":"Schmid S, Svoboda J, Yeo MX. Weighted packet selection for rechargeable links in cryptocurrency networks: Complexity and approximation. In: SIROCCO 2023: Structural Information and Communication Complexity . Vol 13892. Springer Nature; 2023:576-594. doi:10.1007/978-3-031-32733-9_26","short":"S. Schmid, J. Svoboda, M.X. Yeo, in:, SIROCCO 2023: Structural Information and Communication Complexity , Springer Nature, 2023, pp. 576–594.","ieee":"S. Schmid, J. Svoboda, and M. X. Yeo, “Weighted packet selection for rechargeable links in cryptocurrency networks: Complexity and approximation,” in SIROCCO 2023: Structural Information and Communication Complexity , Alcala de Henares, Spain, 2023, vol. 13892, pp. 576–594."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","author":[{"last_name":"Schmid","full_name":"Schmid, Stefan","first_name":"Stefan"},{"orcid":"0000-0002-1419-3267","full_name":"Svoboda, Jakub","last_name":"Svoboda","first_name":"Jakub","id":"130759D2-D7DD-11E9-87D2-DE0DE6697425"},{"first_name":"Michelle X","id":"2D82B818-F248-11E8-B48F-1D18A9856A87","full_name":"Yeo, Michelle X","last_name":"Yeo"}],"external_id":{"arxiv":["2204.13459"]},"article_processing_charge":"No","title":"Weighted packet selection for rechargeable links in cryptocurrency networks: Complexity and approximation","acknowledgement":"We thank Mahsa Bastankhah and Mohammad Ali Maddah-Ali for fruitful discussions about different variants of the problem. This work is supported by the European Research Council (ERC) Consolidator Project 864228 (AdjustNet), 2020-2025, the ERC CoG 863818 (ForM-SMArt), and the German Research Foundation (DFG) grant 470029389 (FlexNets), 2021–2024.","quality_controlled":"1","publisher":"Springer Nature","oa":1,"year":"2023","day":"25","publication":"SIROCCO 2023: Structural Information and Communication Complexity ","page":"576-594","date_published":"2023-05-25T00:00:00Z","doi":"10.1007/978-3-031-32733-9_26","date_created":"2023-07-16T22:01:12Z"},{"department":[{"_id":"KrCh"}],"file_date_updated":"2023-12-11T11:10:32Z","date_updated":"2023-12-11T11:17:53Z","ddc":["000","570"],"article_type":"original","type":"journal_article","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"status":"public","_id":"14657","volume":20,"issue":"208","ec_funded":1,"publication_identifier":{"eissn":["1742-5662"]},"publication_status":"published","file":[{"success":1,"checksum":"2eefab13127c7786dbd33303c482a004","file_id":"14673","relation":"main_file","access_level":"open_access","content_type":"application/pdf","file_name":"2023_RoyalInterface_Tkadlec.pdf","date_created":"2023-12-11T11:10:32Z","creator":"dernst","file_size":1720243,"date_updated":"2023-12-11T11:10:32Z"}],"language":[{"iso":"eng"}],"scopus_import":"1","month":"11","intvolume":" 20","abstract":[{"lang":"eng","text":"Natural selection is usually studied between mutants that differ in reproductive rate, but are subject to the same population structure. Here we explore how natural selection acts on mutants that have the same reproductive rate, but different population structures. In our framework, population structure is given by a graph that specifies where offspring can disperse. The invading mutant disperses offspring on a different graph than the resident wild-type. We find that more densely connected dispersal graphs tend to increase the invader’s fixation probability, but the exact relationship between structure and fixation probability is subtle. We present three main results. First, we prove that if both invader and resident are on complete dispersal graphs, then removing a single edge in the invader’s dispersal graph reduces its fixation probability. Second, we show that for certain island models higher invader’s connectivity increases its fixation probability, but the magnitude of the effect depends on the exact layout of the connections. Third, we show that for lattices the effect of different connectivity is comparable to that of different fitness: for large population size, the invader’s fixation probability is either constant or exponentially small, depending on whether it is more or less connected than the resident."}],"pmid":1,"oa_version":"Published Version","author":[{"id":"3F24CCC8-F248-11E8-B48F-1D18A9856A87","first_name":"Josef","last_name":"Tkadlec","orcid":"0000-0002-1097-9684","full_name":"Tkadlec, Josef"},{"first_name":"Kamran","full_name":"Kaveh, Kamran","last_name":"Kaveh"},{"first_name":"Krishnendu","id":"2E5DCA20-F248-11E8-B48F-1D18A9856A87","full_name":"Chatterjee, Krishnendu","orcid":"0000-0002-4561-241X","last_name":"Chatterjee"},{"last_name":"Nowak","full_name":"Nowak, Martin A.","first_name":"Martin A."}],"article_processing_charge":"Yes (in subscription journal)","external_id":{"pmid":["38016637"]},"title":"Evolutionary dynamics of mutants that modify population structure","citation":{"mla":"Tkadlec, Josef, et al. “Evolutionary Dynamics of Mutants That Modify Population Structure.” Journal of the Royal Society, Interface, vol. 20, no. 208, 20230355, The Royal Society, 2023, doi:10.1098/rsif.2023.0355.","short":"J. Tkadlec, K. Kaveh, K. Chatterjee, M.A. Nowak, Journal of the Royal Society, Interface 20 (2023).","ieee":"J. Tkadlec, K. Kaveh, K. Chatterjee, and M. A. Nowak, “Evolutionary dynamics of mutants that modify population structure,” Journal of the Royal Society, Interface, vol. 20, no. 208. The Royal Society, 2023.","apa":"Tkadlec, J., Kaveh, K., Chatterjee, K., & Nowak, M. A. (2023). Evolutionary dynamics of mutants that modify population structure. Journal of the Royal Society, Interface. The Royal Society. https://doi.org/10.1098/rsif.2023.0355","ama":"Tkadlec J, Kaveh K, Chatterjee K, Nowak MA. Evolutionary dynamics of mutants that modify population structure. Journal of the Royal Society, Interface. 2023;20(208). doi:10.1098/rsif.2023.0355","chicago":"Tkadlec, Josef, Kamran Kaveh, Krishnendu Chatterjee, and Martin A. Nowak. “Evolutionary Dynamics of Mutants That Modify Population Structure.” Journal of the Royal Society, Interface. The Royal Society, 2023. https://doi.org/10.1098/rsif.2023.0355.","ista":"Tkadlec J, Kaveh K, Chatterjee K, Nowak MA. 2023. Evolutionary dynamics of mutants that modify population structure. Journal of the Royal Society, Interface. 20(208), 20230355."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","project":[{"grant_number":"863818","name":"Formal Methods for Stochastic Models: Algorithms and Applications","call_identifier":"H2020","_id":"0599E47C-7A3F-11EA-A408-12923DDC885E"}],"article_number":"20230355","date_published":"2023-11-29T00:00:00Z","doi":"10.1098/rsif.2023.0355","date_created":"2023-12-10T23:00:58Z","has_accepted_license":"1","year":"2023","day":"29","publication":"Journal of the Royal Society, Interface","quality_controlled":"1","publisher":"The Royal Society","oa":1,"acknowledgement":"K.C. acknowledges support from the ERC CoG 863818(ForM-SMArt). J.T. is supported by Center for Foundations ofModern Computer Science (Charles Univ. project UNCE/SCI/004)."},{"type":"journal_article","article_type":"original","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"status":"public","_id":"13258","department":[{"_id":"KrCh"}],"file_date_updated":"2023-07-31T11:32:36Z","date_updated":"2023-12-13T11:42:38Z","ddc":["000"],"scopus_import":"1","month":"07","intvolume":" 14","abstract":[{"lang":"eng","text":"Many human interactions feature the characteristics of social dilemmas where individual actions have consequences for the group and the environment. The feedback between behavior and environment can be studied with the framework of stochastic games. In stochastic games, the state of the environment can change, depending on the choices made by group members. Past work suggests that such feedback can reinforce cooperative behaviors. In particular, cooperation can evolve in stochastic games even if it is infeasible in each separate repeated game. In stochastic games, participants have an interest in conditioning their strategies on the state of the environment. Yet in many applications, precise information about the state could be scarce. Here, we study how the availability of information (or lack thereof) shapes evolution of cooperation. Already for simple examples of two state games we find surprising effects. In some cases, cooperation is only possible if there is precise information about the state of the environment. In other cases, cooperation is most abundant when there is no information about the state of the environment. We systematically analyze all stochastic games of a given complexity class, to determine when receiving information about the environment is better, neutral, or worse for evolution of cooperation."}],"pmid":1,"oa_version":"Published Version","volume":14,"related_material":{"record":[{"relation":"research_data","id":"13336","status":"public"}]},"ec_funded":1,"publication_identifier":{"eissn":["2041-1723"]},"publication_status":"published","file":[{"creator":"dernst","file_size":1601682,"date_updated":"2023-07-31T11:32:36Z","file_name":"2023_NatureComm_Kleshnina.pdf","date_created":"2023-07-31T11:32:36Z","relation":"main_file","access_level":"open_access","content_type":"application/pdf","success":1,"file_id":"13337","checksum":"5aceefdfe76686267b93ae4fe81899f1"}],"language":[{"iso":"eng"}],"project":[{"name":"Formal Methods for Stochastic Models: Algorithms and Applications","grant_number":"863818","call_identifier":"H2020","_id":"0599E47C-7A3F-11EA-A408-12923DDC885E"},{"grant_number":"754411","name":"ISTplus - Postdoctoral Fellowships","_id":"260C2330-B435-11E9-9278-68D0E5697425","call_identifier":"H2020"}],"article_number":"4153","author":[{"id":"4E21749C-F248-11E8-B48F-1D18A9856A87","first_name":"Maria","last_name":"Kleshnina","full_name":"Kleshnina, Maria"},{"id":"2FDF8F3C-F248-11E8-B48F-1D18A9856A87","first_name":"Christian","last_name":"Hilbe","orcid":"0000-0001-5116-955X","full_name":"Hilbe, Christian"},{"orcid":"0000-0001-6687-1210","full_name":"Simsa, Stepan","last_name":"Simsa","id":"409d615c-2f95-11ee-b934-90a352102c1e","first_name":"Stepan"},{"last_name":"Chatterjee","full_name":"Chatterjee, Krishnendu","orcid":"0000-0002-4561-241X","id":"2E5DCA20-F248-11E8-B48F-1D18A9856A87","first_name":"Krishnendu"},{"first_name":"Martin A.","full_name":"Nowak, Martin A.","last_name":"Nowak"}],"article_processing_charge":"Yes","external_id":{"isi":["001029450400031"],"pmid":["37438341"]},"title":"The effect of environmental information on evolution of cooperation in stochastic games","citation":{"mla":"Kleshnina, Maria, et al. “The Effect of Environmental Information on Evolution of Cooperation in Stochastic Games.” Nature Communications, vol. 14, 4153, Springer Nature, 2023, doi:10.1038/s41467-023-39625-9.","ama":"Kleshnina M, Hilbe C, Simsa S, Chatterjee K, Nowak MA. The effect of environmental information on evolution of cooperation in stochastic games. Nature Communications. 2023;14. doi:10.1038/s41467-023-39625-9","apa":"Kleshnina, M., Hilbe, C., Simsa, S., Chatterjee, K., & Nowak, M. A. (2023). The effect of environmental information on evolution of cooperation in stochastic games. Nature Communications. Springer Nature. https://doi.org/10.1038/s41467-023-39625-9","short":"M. Kleshnina, C. Hilbe, S. Simsa, K. Chatterjee, M.A. Nowak, Nature Communications 14 (2023).","ieee":"M. Kleshnina, C. Hilbe, S. Simsa, K. Chatterjee, and M. A. Nowak, “The effect of environmental information on evolution of cooperation in stochastic games,” Nature Communications, vol. 14. Springer Nature, 2023.","chicago":"Kleshnina, Maria, Christian Hilbe, Stepan Simsa, Krishnendu Chatterjee, and Martin A. Nowak. “The Effect of Environmental Information on Evolution of Cooperation in Stochastic Games.” Nature Communications. Springer Nature, 2023. https://doi.org/10.1038/s41467-023-39625-9.","ista":"Kleshnina M, Hilbe C, Simsa S, Chatterjee K, Nowak MA. 2023. The effect of environmental information on evolution of cooperation in stochastic games. Nature Communications. 14, 4153."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publisher":"Springer Nature","quality_controlled":"1","oa":1,"acknowledgement":"This work was supported by the European Research Council CoG 863818 (ForM-SMArt) (to K.C.), the European Research Council Starting Grant 850529: E-DIRECT (to C.H.), the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant Agreement #754411 and the French Agence Nationale de la Recherche (under the Investissement d’Avenir programme, ANR-17-EURE-0010) (to M.K.).","doi":"10.1038/s41467-023-39625-9","date_published":"2023-07-12T00:00:00Z","date_created":"2023-07-23T22:01:11Z","isi":1,"has_accepted_license":"1","year":"2023","day":"12","publication":"Nature Communications"},{"_id":"13336","type":"research_data_reference","status":"public","date_updated":"2023-12-13T11:42:37Z","citation":{"ista":"Kleshnina M. 2023. kleshnina/stochgames_info: The effect of environmental information on evolution of cooperation in stochastic games, Zenodo, 10.5281/ZENODO.8059564.","chicago":"Kleshnina, Maria. “Kleshnina/Stochgames_info: The Effect of Environmental Information on Evolution of Cooperation in Stochastic Games.” Zenodo, 2023. https://doi.org/10.5281/ZENODO.8059564.","apa":"Kleshnina, M. (2023). kleshnina/stochgames_info: The effect of environmental information on evolution of cooperation in stochastic games. Zenodo. https://doi.org/10.5281/ZENODO.8059564","ama":"Kleshnina M. kleshnina/stochgames_info: The effect of environmental information on evolution of cooperation in stochastic games. 2023. doi:10.5281/ZENODO.8059564","ieee":"M. Kleshnina, “kleshnina/stochgames_info: The effect of environmental information on evolution of cooperation in stochastic games.” Zenodo, 2023.","short":"M. Kleshnina, (2023).","mla":"Kleshnina, Maria. Kleshnina/Stochgames_info: The Effect of Environmental Information on Evolution of Cooperation in Stochastic Games. Zenodo, 2023, doi:10.5281/ZENODO.8059564."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","ddc":["000"],"author":[{"id":"4E21749C-F248-11E8-B48F-1D18A9856A87","first_name":"Maria","last_name":"Kleshnina","full_name":"Kleshnina, Maria"}],"article_processing_charge":"No","title":"kleshnina/stochgames_info: The effect of environmental information on evolution of cooperation in stochastic games","department":[{"_id":"KrCh"}],"oa_version":"Published Version","publisher":"Zenodo","oa":1,"main_file_link":[{"url":"https://doi.org/10.5281/zenodo.8059564","open_access":"1"}],"month":"06","year":"2023","day":"20","date_published":"2023-06-20T00:00:00Z","related_material":{"record":[{"status":"public","id":"13258","relation":"used_in_publication"}]},"doi":"10.5281/ZENODO.8059564","date_created":"2023-07-31T11:30:46Z"},{"date_updated":"2023-12-13T12:06:10Z","department":[{"_id":"KrCh"}],"_id":"13967","status":"public","type":"conference","conference":{"end_date":"2023-06-29","location":"Boston, MA, United States","start_date":"2023-06-26","name":"LICS: Symposium on Logic in Computer Science"},"language":[{"iso":"eng"}],"publication_identifier":{"issn":["1043-6871"],"isbn":["9798350335873"]},"publication_status":"published","volume":2023,"oa_version":"Preprint","abstract":[{"text":"A classic solution technique for Markov decision processes (MDP) and stochastic games (SG) is value iteration (VI). Due to its good practical performance, this approximative approach is typically preferred over exact techniques, even though no practical bounds on the imprecision of the result could be given until recently. As a consequence, even the most used model checkers could return arbitrarily wrong results. Over the past decade, different works derived stopping criteria, indicating when the precision reaches the desired level, for various settings, in particular MDP with reachability, total reward, and mean payoff, and SG with reachability.In this paper, we provide the first stopping criteria for VI on SG with total reward and mean payoff, yielding the first anytime algorithms in these settings. To this end, we provide the solution in two flavours: First through a reduction to the MDP case and second directly on SG. The former is simpler and automatically utilizes any advances on MDP. The latter allows for more local computations, heading towards better practical efficiency.Our solution unifies the previously mentioned approaches for MDP and SG and their underlying ideas. To achieve this, we isolate objective-specific subroutines as well as identify objective-independent concepts. These structural concepts, while surprisingly simple, form the very essence of the unified solution.","lang":"eng"}],"month":"07","intvolume":" 2023","scopus_import":"1","main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.2304.09930"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"mla":"Kretinsky, Jan, et al. “Stopping Criteria for Value Iteration on Stochastic Games with Quantitative Objectives.” 38th Annual ACM/IEEE Symposium on Logic in Computer Science, vol. 2023, Institute of Electrical and Electronics Engineers, 2023, doi:10.1109/LICS56636.2023.10175771.","ama":"Kretinsky J, Meggendorfer T, Weininger M. Stopping criteria for value iteration on stochastic games with quantitative objectives. In: 38th Annual ACM/IEEE Symposium on Logic in Computer Science. Vol 2023. Institute of Electrical and Electronics Engineers; 2023. doi:10.1109/LICS56636.2023.10175771","apa":"Kretinsky, J., Meggendorfer, T., & Weininger, M. (2023). Stopping criteria for value iteration on stochastic games with quantitative objectives. In 38th Annual ACM/IEEE Symposium on Logic in Computer Science (Vol. 2023). Boston, MA, United States: Institute of Electrical and Electronics Engineers. https://doi.org/10.1109/LICS56636.2023.10175771","short":"J. Kretinsky, T. Meggendorfer, M. Weininger, in:, 38th Annual ACM/IEEE Symposium on Logic in Computer Science, Institute of Electrical and Electronics Engineers, 2023.","ieee":"J. Kretinsky, T. Meggendorfer, and M. Weininger, “Stopping criteria for value iteration on stochastic games with quantitative objectives,” in 38th Annual ACM/IEEE Symposium on Logic in Computer Science, Boston, MA, United States, 2023, vol. 2023.","chicago":"Kretinsky, Jan, Tobias Meggendorfer, and Maximilian Weininger. “Stopping Criteria for Value Iteration on Stochastic Games with Quantitative Objectives.” In 38th Annual ACM/IEEE Symposium on Logic in Computer Science, Vol. 2023. Institute of Electrical and Electronics Engineers, 2023. https://doi.org/10.1109/LICS56636.2023.10175771.","ista":"Kretinsky J, Meggendorfer T, Weininger M. 2023. Stopping criteria for value iteration on stochastic games with quantitative objectives. 38th Annual ACM/IEEE Symposium on Logic in Computer Science. LICS: Symposium on Logic in Computer Science vol. 2023."},"title":"Stopping criteria for value iteration on stochastic games with quantitative objectives","author":[{"orcid":"0000-0002-8122-2881","full_name":"Kretinsky, Jan","last_name":"Kretinsky","id":"44CEF464-F248-11E8-B48F-1D18A9856A87","first_name":"Jan"},{"last_name":"Meggendorfer","full_name":"Meggendorfer, Tobias","orcid":"0000-0002-1712-2165","first_name":"Tobias","id":"b21b0c15-30a2-11eb-80dc-f13ca25802e1"},{"first_name":"Maximilian","id":"02ab0197-cc70-11ed-ab61-918e71f56881","last_name":"Weininger","full_name":"Weininger, Maximilian"}],"external_id":{"arxiv":["2304.09930"],"isi":["001036707700042"]},"article_processing_charge":"No","day":"01","publication":"38th Annual ACM/IEEE Symposium on Logic in Computer Science","isi":1,"year":"2023","date_published":"2023-07-01T00:00:00Z","doi":"10.1109/LICS56636.2023.10175771","date_created":"2023-08-06T22:01:10Z","acknowledgement":"This research was funded in part by DFG projects 383882557 “SUV” and 427755713 “GOPro”.","quality_controlled":"1","publisher":"Institute of Electrical and Electronics Engineers","oa":1},{"status":"public","type":"journal_article","article_type":"original","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"_id":"12833","file_date_updated":"2023-04-17T08:10:28Z","department":[{"_id":"KrCh"},{"_id":"HeEd"},{"_id":"UlWa"}],"ddc":["000"],"date_updated":"2024-01-04T12:42:09Z","month":"01","intvolume":" 24","scopus_import":"1","oa_version":"Published Version","abstract":[{"lang":"eng","text":"The input to the token swapping problem is a graph with vertices v1, v2, . . . , vn, and n tokens with labels 1,2, . . . , n, one on each vertex. The goal is to get token i to vertex vi for all i= 1, . . . , n using a minimum number of swaps, where a swap exchanges the tokens on the endpoints of an edge.Token swapping on a tree, also known as “sorting with a transposition tree,” is not known to be in P nor NP-complete. We present some partial results: 1. An optimum swap sequence may need to perform a swap on a leaf vertex that has the correct token (a “happy leaf”), disproving a conjecture of Vaughan. 2. Any algorithm that fixes happy leaves—as all known approximation algorithms for the problem do—has approximation factor at least 4/3. Furthermore, the two best-known 2-approximation algorithms have approximation factor exactly 2. 3. A generalized problem—weighted coloured token swapping—is NP-complete on trees, but solvable in polynomial time on paths and stars. In this version, tokens and vertices have colours, and colours have weights. The goal is to get every token to a vertex of the same colour, and the cost of a swap is the sum of the weights of the two tokens involved."}],"issue":"2","volume":24,"related_material":{"record":[{"relation":"earlier_version","status":"public","id":"7950"}]},"file":[{"checksum":"439102ea4f6e2aeefd7107dfb9ccf532","file_id":"12844","success":1,"access_level":"open_access","relation":"main_file","content_type":"application/pdf","date_created":"2023-04-17T08:10:28Z","file_name":"2022_DMTCS_Biniaz.pdf","creator":"dernst","date_updated":"2023-04-17T08:10:28Z","file_size":2072197}],"language":[{"iso":"eng"}],"publication_identifier":{"issn":["1462-7264"],"eissn":["1365-8050"]},"publication_status":"published","article_number":"9","title":"Token swapping on trees","author":[{"first_name":"Ahmad","full_name":"Biniaz, Ahmad","last_name":"Biniaz"},{"first_name":"Kshitij","full_name":"Jain, Kshitij","last_name":"Jain"},{"last_name":"Lubiw","full_name":"Lubiw, Anna","first_name":"Anna"},{"first_name":"Zuzana","id":"45CFE238-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-6660-1322","full_name":"Masárová, Zuzana","last_name":"Masárová"},{"first_name":"Tillmann","full_name":"Miltzow, Tillmann","last_name":"Miltzow"},{"full_name":"Mondal, Debajyoti","last_name":"Mondal","first_name":"Debajyoti"},{"first_name":"Anurag Murty","full_name":"Naredla, Anurag Murty","last_name":"Naredla"},{"last_name":"Tkadlec","orcid":"0000-0002-1097-9684","full_name":"Tkadlec, Josef","id":"3F24CCC8-F248-11E8-B48F-1D18A9856A87","first_name":"Josef"},{"first_name":"Alexi","last_name":"Turcotte","full_name":"Turcotte, Alexi"}],"article_processing_charge":"No","external_id":{"arxiv":["1903.06981"]},"user_id":"3E5EF7F0-F248-11E8-B48F-1D18A9856A87","citation":{"chicago":"Biniaz, Ahmad, Kshitij Jain, Anna Lubiw, Zuzana Masárová, Tillmann Miltzow, Debajyoti Mondal, Anurag Murty Naredla, Josef Tkadlec, and Alexi Turcotte. “Token Swapping on Trees.” Discrete Mathematics and Theoretical Computer Science. EPI Sciences, 2023. https://doi.org/10.46298/DMTCS.8383.","ista":"Biniaz A, Jain K, Lubiw A, Masárová Z, Miltzow T, Mondal D, Naredla AM, Tkadlec J, Turcotte A. 2023. Token swapping on trees. Discrete Mathematics and Theoretical Computer Science. 24(2), 9.","mla":"Biniaz, Ahmad, et al. “Token Swapping on Trees.” Discrete Mathematics and Theoretical Computer Science, vol. 24, no. 2, 9, EPI Sciences, 2023, doi:10.46298/DMTCS.8383.","ieee":"A. Biniaz et al., “Token swapping on trees,” Discrete Mathematics and Theoretical Computer Science, vol. 24, no. 2. EPI Sciences, 2023.","short":"A. Biniaz, K. Jain, A. Lubiw, Z. Masárová, T. Miltzow, D. Mondal, A.M. Naredla, J. Tkadlec, A. Turcotte, Discrete Mathematics and Theoretical Computer Science 24 (2023).","apa":"Biniaz, A., Jain, K., Lubiw, A., Masárová, Z., Miltzow, T., Mondal, D., … Turcotte, A. (2023). Token swapping on trees. Discrete Mathematics and Theoretical Computer Science. EPI Sciences. https://doi.org/10.46298/DMTCS.8383","ama":"Biniaz A, Jain K, Lubiw A, et al. Token swapping on trees. Discrete Mathematics and Theoretical Computer Science. 2023;24(2). doi:10.46298/DMTCS.8383"},"quality_controlled":"1","publisher":"EPI Sciences","oa":1,"acknowledgement":"This work was begun at the University of Waterloo and was partially supported by the Natural Sciences and Engineering Council of Canada (NSERC).\r\n","date_published":"2023-01-18T00:00:00Z","doi":"10.46298/DMTCS.8383","date_created":"2023-04-16T22:01:08Z","day":"18","publication":"Discrete Mathematics and Theoretical Computer Science","has_accepted_license":"1","year":"2023"}]