---
_id: '551'
abstract:
- lang: eng
  text: 'Evolutionary graph theory studies the evolutionary dynamics in a population
    structure given as a connected graph. Each node of the graph represents an individual
    of the population, and edges determine how offspring are placed. We consider the
    classical birth-death Moran process where there are two types of individuals,
    namely, the residents with fitness 1 and mutants with fitness r. The fitness indicates
    the reproductive strength. The evolutionary dynamics happens as follows: in the
    initial step, in a population of all resident individuals a mutant is introduced,
    and then at each step, an individual is chosen proportional to the fitness of
    its type to reproduce, and the offspring replaces a neighbor uniformly at random.
    The process stops when all individuals are either residents or mutants. The probability
    that all individuals in the end are mutants is called the fixation probability,
    which is a key factor in the rate of evolution. We consider the problem of approximating
    the fixation probability. The class of algorithms that is extremely relevant for
    approximation of the fixation probabilities is the Monte-Carlo simulation of the
    process. Previous results present a polynomial-time Monte-Carlo algorithm for
    undirected graphs when r is given in unary. First, we present a simple modification:
    instead of simulating each step, we discard ineffective steps, where no node changes
    type (i.e., either residents replace residents, or mutants replace mutants). Using
    the above simple modification and our result that the number of effective steps
    is concentrated around the expected number of effective steps, we present faster
    polynomial-time Monte-Carlo algorithms for undirected graphs. Our algorithms are
    always at least a factor O(n2/ log n) faster as compared to the previous algorithms,
    where n is the number of nodes, and is polynomial even if r is given in binary.
    We also present lower bounds showing that the upper bound on the expected number
    of effective steps we present is asymptotically tight for undirected graphs. '
alternative_title:
- LIPIcs
article_number: '61'
author:
- first_name: Krishnendu
  full_name: Chatterjee, Krishnendu
  id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87
  last_name: Chatterjee
  orcid: 0000-0002-4561-241X
- first_name: Rasmus
  full_name: Ibsen-Jensen, Rasmus
  id: 3B699956-F248-11E8-B48F-1D18A9856A87
  last_name: Ibsen-Jensen
  orcid: 0000-0003-4783-0389
- first_name: Martin
  full_name: Nowak, Martin
  last_name: Nowak
citation:
  ama: 'Chatterjee K, Ibsen-Jensen R, Nowak M. Faster Monte Carlo algorithms for fixation
    probability of the Moran process on undirected graphs. In: <i>Leibniz International
    Proceedings in Informatics</i>. Vol 83. Schloss Dagstuhl - Leibniz-Zentrum für
    Informatik; 2017. doi:<a href="https://doi.org/10.4230/LIPIcs.MFCS.2017.61">10.4230/LIPIcs.MFCS.2017.61</a>'
  apa: 'Chatterjee, K., Ibsen-Jensen, R., &#38; Nowak, M. (2017). Faster Monte Carlo
    algorithms for fixation probability of the Moran process on undirected graphs.
    In <i>Leibniz International Proceedings in Informatics</i> (Vol. 83). Aalborg,
    Denmark: Schloss Dagstuhl - Leibniz-Zentrum für Informatik. <a href="https://doi.org/10.4230/LIPIcs.MFCS.2017.61">https://doi.org/10.4230/LIPIcs.MFCS.2017.61</a>'
  chicago: Chatterjee, Krishnendu, Rasmus Ibsen-Jensen, and Martin Nowak. “Faster
    Monte Carlo Algorithms for Fixation Probability of the Moran Process on Undirected
    Graphs.” In <i>Leibniz International Proceedings in Informatics</i>, Vol. 83.
    Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2017. <a href="https://doi.org/10.4230/LIPIcs.MFCS.2017.61">https://doi.org/10.4230/LIPIcs.MFCS.2017.61</a>.
  ieee: K. Chatterjee, R. Ibsen-Jensen, and M. Nowak, “Faster Monte Carlo algorithms
    for fixation probability of the Moran process on undirected graphs,” in <i>Leibniz
    International Proceedings in Informatics</i>, Aalborg, Denmark, 2017, vol. 83.
  ista: 'Chatterjee K, Ibsen-Jensen R, Nowak M. 2017. Faster Monte Carlo algorithms
    for fixation probability of the Moran process on undirected graphs. Leibniz International
    Proceedings in Informatics. MFCS: Mathematical Foundations of Computer Science
    (SG), LIPIcs, vol. 83, 61.'
  mla: Chatterjee, Krishnendu, et al. “Faster Monte Carlo Algorithms for Fixation
    Probability of the Moran Process on Undirected Graphs.” <i>Leibniz International
    Proceedings in Informatics</i>, vol. 83, 61, Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik, 2017, doi:<a href="https://doi.org/10.4230/LIPIcs.MFCS.2017.61">10.4230/LIPIcs.MFCS.2017.61</a>.
  short: K. Chatterjee, R. Ibsen-Jensen, M. Nowak, in:, Leibniz International Proceedings
    in Informatics, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2017.
conference:
  end_date: 2017-08-25
  location: Aalborg, Denmark
  name: 'MFCS: Mathematical Foundations of Computer Science (SG)'
  start_date: 2017-08-21
date_created: 2018-12-11T11:47:08Z
date_published: 2017-11-01T00:00:00Z
date_updated: 2021-01-12T08:02:34Z
day: '01'
ddc:
- '004'
department:
- _id: KrCh
doi: 10.4230/LIPIcs.MFCS.2017.61
file:
- access_level: open_access
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  creator: system
  date_created: 2018-12-12T10:18:04Z
  date_updated: 2020-07-14T12:47:00Z
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file_date_updated: 2020-07-14T12:47:00Z
has_accepted_license: '1'
intvolume: '        83'
language:
- iso: eng
month: '11'
oa: 1
oa_version: Published Version
publication: Leibniz International Proceedings in Informatics
publication_identifier:
  isbn:
  - 978-395977046-0
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
publist_id: '7263'
pubrep_id: '924'
quality_controlled: '1'
scopus_import: 1
status: public
title: Faster Monte Carlo algorithms for fixation probability of the Moran process
  on undirected graphs
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: conference
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
volume: 83
year: '2017'
...
---
_id: '552'
abstract:
- lang: eng
  text: 'Graph games provide the foundation for modeling and synthesis of reactive
    processes. Such games are played over graphs where the vertices are controlled
    by two adversarial players. We consider graph games where the objective of the
    first player is the conjunction of a qualitative objective (specified as a parity
    condition) and a quantitative objective (specified as a meanpayoff condition).
    There are two variants of the problem, namely, the threshold problem where the
    quantitative goal is to ensure that the mean-payoff value is above a threshold,
    and the value problem where the quantitative goal is to ensure the optimal mean-payoff
    value; in both cases ensuring the qualitative parity objective. The previous best-known
    algorithms for game graphs with n vertices, m edges, parity objectives with d
    priorities, and maximal absolute reward value W for mean-payoff objectives, are
    as follows: O(nd+1 . m . w) for the threshold problem, and O(nd+2 · m · W) for
    the value problem. Our main contributions are faster algorithms, and the running
    times of our algorithms are as follows: O(nd-1 · m ·W) for the threshold problem,
    and O(nd · m · W · log(n · W)) for the value problem. For mean-payoff parity objectives
    with two priorities, our algorithms match the best-known bounds of the algorithms
    for mean-payoff games (without conjunction with parity objectives). Our results
    are relevant in synthesis of reactive systems with both functional requirement
    (given as a qualitative objective) and performance requirement (given as a quantitative
    objective).'
alternative_title:
- LIPIcs
article_number: '39'
article_processing_charge: No
author:
- first_name: Krishnendu
  full_name: Chatterjee, Krishnendu
  id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87
  last_name: Chatterjee
  orcid: 0000-0002-4561-241X
- first_name: Monika H
  full_name: Henzinger, Monika H
  id: 540c9bbd-f2de-11ec-812d-d04a5be85630
  last_name: Henzinger
  orcid: 0000-0002-5008-6530
- first_name: Alexander
  full_name: Svozil, Alexander
  last_name: Svozil
citation:
  ama: 'Chatterjee K, Henzinger MH, Svozil A. Faster algorithms for mean-payoff parity
    games. In: <i>Leibniz International Proceedings in Informatics</i>. Vol 83. Schloss
    Dagstuhl - Leibniz-Zentrum für Informatik; 2017. doi:<a href="https://doi.org/10.4230/LIPIcs.MFCS.2017.39">10.4230/LIPIcs.MFCS.2017.39</a>'
  apa: 'Chatterjee, K., Henzinger, M. H., &#38; Svozil, A. (2017). Faster algorithms
    for mean-payoff parity games. In <i>Leibniz International Proceedings in Informatics</i>
    (Vol. 83). Aalborg, Denmark: Schloss Dagstuhl - Leibniz-Zentrum für Informatik.
    <a href="https://doi.org/10.4230/LIPIcs.MFCS.2017.39">https://doi.org/10.4230/LIPIcs.MFCS.2017.39</a>'
  chicago: Chatterjee, Krishnendu, Monika H Henzinger, and Alexander Svozil. “Faster
    Algorithms for Mean-Payoff Parity Games.” In <i>Leibniz International Proceedings
    in Informatics</i>, Vol. 83. Schloss Dagstuhl - Leibniz-Zentrum für Informatik,
    2017. <a href="https://doi.org/10.4230/LIPIcs.MFCS.2017.39">https://doi.org/10.4230/LIPIcs.MFCS.2017.39</a>.
  ieee: K. Chatterjee, M. H. Henzinger, and A. Svozil, “Faster algorithms for mean-payoff
    parity games,” in <i>Leibniz International Proceedings in Informatics</i>, Aalborg,
    Denmark, 2017, vol. 83.
  ista: 'Chatterjee K, Henzinger MH, Svozil A. 2017. Faster algorithms for mean-payoff
    parity games. Leibniz International Proceedings in Informatics. MFCS: Mathematical
    Foundations of Computer Science (SG), LIPIcs, vol. 83, 39.'
  mla: Chatterjee, Krishnendu, et al. “Faster Algorithms for Mean-Payoff Parity Games.”
    <i>Leibniz International Proceedings in Informatics</i>, vol. 83, 39, Schloss
    Dagstuhl - Leibniz-Zentrum für Informatik, 2017, doi:<a href="https://doi.org/10.4230/LIPIcs.MFCS.2017.39">10.4230/LIPIcs.MFCS.2017.39</a>.
  short: K. Chatterjee, M.H. Henzinger, A. Svozil, in:, Leibniz International Proceedings
    in Informatics, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2017.
conference:
  end_date: 2017-08-25
  location: Aalborg, Denmark
  name: 'MFCS: Mathematical Foundations of Computer Science (SG)'
  start_date: 2017-08-21
date_created: 2018-12-11T11:47:08Z
date_published: 2017-11-01T00:00:00Z
date_updated: 2023-02-14T10:06:46Z
day: '01'
ddc:
- '004'
department:
- _id: KrCh
doi: 10.4230/LIPIcs.MFCS.2017.39
ec_funded: 1
file:
- access_level: open_access
  checksum: c67f4866ddbfd555afef1f63ae9a8fc7
  content_type: application/pdf
  creator: system
  date_created: 2018-12-12T10:16:57Z
  date_updated: 2020-07-14T12:47:00Z
  file_id: '5248'
  file_name: IST-2018-923-v1+1_LIPIcs-MFCS-2017-39.pdf
  file_size: 610339
  relation: main_file
file_date_updated: 2020-07-14T12:47:00Z
has_accepted_license: '1'
intvolume: '        83'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/3.0/
month: '11'
oa: 1
oa_version: Published Version
project:
- _id: 25863FF4-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: S11407
  name: Game Theory
- _id: 2581B60A-B435-11E9-9278-68D0E5697425
  call_identifier: FP7
  grant_number: '279307'
  name: 'Quantitative Graph Games: Theory and Applications'
publication: Leibniz International Proceedings in Informatics
publication_identifier:
  isbn:
  - 978-395977046-0
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
publist_id: '7262'
pubrep_id: '923'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Faster algorithms for mean-payoff parity games
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/3.0/legalcode
  name: Creative Commons Attribution 3.0 Unported (CC BY 3.0)
  short: CC BY (3.0)
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 83
year: '2017'
...
---
_id: '553'
abstract:
- lang: eng
  text: 'We consider two player, zero-sum, finite-state concurrent reachability games,
    played for an infinite number of rounds, where in every round, each player simultaneously
    and independently of the other players chooses an action, whereafter the successor
    state is determined by a probability distribution given by the current state and
    the chosen actions. Player 1 wins iff a designated goal state is eventually visited.
    We are interested in the complexity of stationary strategies measured by their
    patience, which is defined as the inverse of the smallest non-zero probability
    employed. Our main results are as follows: We show that: (i) the optimal bound
    on the patience of optimal and -optimal strategies, for both players is doubly
    exponential; and (ii) even in games with a single non-absorbing state exponential
    (in the number of actions) patience is necessary. '
alternative_title:
- LIPIcs
article_number: '55'
author:
- first_name: Krishnendu
  full_name: Chatterjee, Krishnendu
  id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87
  last_name: Chatterjee
  orcid: 0000-0002-4561-241X
- first_name: Kristofer
  full_name: Hansen, Kristofer
  last_name: Hansen
- first_name: Rasmus
  full_name: Ibsen-Jensen, Rasmus
  id: 3B699956-F248-11E8-B48F-1D18A9856A87
  last_name: Ibsen-Jensen
  orcid: 0000-0003-4783-0389
citation:
  ama: 'Chatterjee K, Hansen K, Ibsen-Jensen R. Strategy complexity of concurrent
    safety games. In: <i>Leibniz International Proceedings in Informatics</i>. Vol
    83. Schloss Dagstuhl - Leibniz-Zentrum für Informatik; 2017. doi:<a href="https://doi.org/10.4230/LIPIcs.MFCS.2017.55">10.4230/LIPIcs.MFCS.2017.55</a>'
  apa: 'Chatterjee, K., Hansen, K., &#38; Ibsen-Jensen, R. (2017). Strategy complexity
    of concurrent safety games. In <i>Leibniz International Proceedings in Informatics</i>
    (Vol. 83). Aalborg, Denmark: Schloss Dagstuhl - Leibniz-Zentrum für Informatik.
    <a href="https://doi.org/10.4230/LIPIcs.MFCS.2017.55">https://doi.org/10.4230/LIPIcs.MFCS.2017.55</a>'
  chicago: Chatterjee, Krishnendu, Kristofer Hansen, and Rasmus Ibsen-Jensen. “Strategy
    Complexity of Concurrent Safety Games.” In <i>Leibniz International Proceedings
    in Informatics</i>, Vol. 83. Schloss Dagstuhl - Leibniz-Zentrum für Informatik,
    2017. <a href="https://doi.org/10.4230/LIPIcs.MFCS.2017.55">https://doi.org/10.4230/LIPIcs.MFCS.2017.55</a>.
  ieee: K. Chatterjee, K. Hansen, and R. Ibsen-Jensen, “Strategy complexity of concurrent
    safety games,” in <i>Leibniz International Proceedings in Informatics</i>, Aalborg,
    Denmark, 2017, vol. 83.
  ista: 'Chatterjee K, Hansen K, Ibsen-Jensen R. 2017. Strategy complexity of concurrent
    safety games. Leibniz International Proceedings in Informatics. MFCS: Mathematical
    Foundations of Computer Science (SG), LIPIcs, vol. 83, 55.'
  mla: Chatterjee, Krishnendu, et al. “Strategy Complexity of Concurrent Safety Games.”
    <i>Leibniz International Proceedings in Informatics</i>, vol. 83, 55, Schloss
    Dagstuhl - Leibniz-Zentrum für Informatik, 2017, doi:<a href="https://doi.org/10.4230/LIPIcs.MFCS.2017.55">10.4230/LIPIcs.MFCS.2017.55</a>.
  short: K. Chatterjee, K. Hansen, R. Ibsen-Jensen, in:, Leibniz International Proceedings
    in Informatics, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2017.
conference:
  end_date: 2017-08-25
  location: Aalborg, Denmark
  name: 'MFCS: Mathematical Foundations of Computer Science (SG)'
  start_date: 2017-08-21
date_created: 2018-12-11T11:47:08Z
date_published: 2017-11-01T00:00:00Z
date_updated: 2021-01-12T08:02:35Z
day: '01'
ddc:
- '004'
department:
- _id: KrCh
doi: 10.4230/LIPIcs.MFCS.2017.55
file:
- access_level: open_access
  checksum: 7101facb56ade363205c695d72dbd173
  content_type: application/pdf
  creator: system
  date_created: 2018-12-12T10:09:29Z
  date_updated: 2020-07-14T12:47:00Z
  file_id: '4753'
  file_name: IST-2018-922-v1+1_LIPIcs-MFCS-2017-55.pdf
  file_size: 549967
  relation: main_file
file_date_updated: 2020-07-14T12:47:00Z
has_accepted_license: '1'
intvolume: '        83'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1506.02434
month: '11'
oa: 1
oa_version: Published Version
publication: Leibniz International Proceedings in Informatics
publication_identifier:
  isbn:
  - 978-395977046-0
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
publist_id: '7261'
pubrep_id: '922'
quality_controlled: '1'
scopus_import: 1
status: public
title: Strategy complexity of concurrent safety games
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  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: conference
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
volume: 83
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...
