---
OA_place: publisher
OA_type: gold
_id: '22002'
abstract:
- lang: eng
  text: Topological simplification is the process of reducing complexity of a function
    while maintaining its essential features. Its goal is to find a new filter function,
    which reorders cells of the input complex in a way which eliminates some persistent
    homological features, without affecting the rest. We present a new approach to
    simplification based on the concept of forbidden regions and combinatorial dynamics.
    It allows us to reorder and cancel critical values, whose cancellation is not
    possible using existing methods because they are not consecutive in the total
    order. Each such cancellation takes O(c⋅n) time in the worst case, where c is
    the number of birth-death pairs and n is the size of the input complex.
acknowledgement: "Jakub Leśkiewicz wants to thank his supervisor, Prof. Marian Mrozek,
  forscientific guidance, patience, and opportunity to delay the rest of his duties
  while writing this work.\r\nThe author also extends thanks to his entire family,
  to Zuzanna Świątek, and to Mikołaj Kardyś,\r\nBEng, MSc, for providing meals during
  the most intensive periods of work. Jakub Leśkiewicz: The research was partially
  funded by the Polish National Science Center under Opus Grant No. 2019/35/B/ST1/00874
  and Opus Grant 2025/57/B/ST1/00550. Bartosz Furmanek: The research was partially
  funded by the Polish National Science Center under Opus Grant No. 2019/35/B/ST1/00874
  and Opus Grant 2025/57/B/ST1/00550. Michał Lipiński: This project has received funding
  from the European Union’s Horizon 2020 research and innovation programme under the
  Marie Skłodowska-Curie Grant Agreement No. 101034413. \r\nDmitriy Morozov: This
  work was supported in part by the U.S. Department of Energy, Office\r\nof Science,
  Office of Advanced Scientific Computing Research, under Contract No. DE-AC02-\r\n05CH11231."
alternative_title:
- LIPIcs
article_number: 72:1-72:17
article_processing_charge: No
arxiv: 1
author:
- first_name: Jakub
  full_name: Leśkiewicz, Jakub
  last_name: Leśkiewicz
- first_name: Bartosz
  full_name: Furmanek, Bartosz
  last_name: Furmanek
- first_name: Michał
  full_name: Lipiński, Michał
  id: dfffb474-4317-11ee-8f5c-fe3fc95a425e
  last_name: Lipiński
  orcid: 0000-0001-9789-9750
- first_name: Dmitriy
  full_name: Morozov, Dmitriy
  last_name: Morozov
citation:
  ama: 'Leśkiewicz J, Furmanek B, Lipiński M, Morozov D. Topological simplification
    guided by forbidden regions. In: <i>42nd International Symposium on Computational
    Geometry</i>. Vol 367. Schloss Dagstuhl - Leibniz-Zentrum für Informatik; 2026.
    doi:<a href="https://doi.org/10.4230/LIPIcs.SoCG.2026.72">10.4230/LIPIcs.SoCG.2026.72</a>'
  apa: 'Leśkiewicz, J., Furmanek, B., Lipiński, M., &#38; Morozov, D. (2026). Topological
    simplification guided by forbidden regions. In <i>42nd International Symposium
    on Computational Geometry</i> (Vol. 367). New Brunswick, NJ, United States: Schloss
    Dagstuhl - Leibniz-Zentrum für Informatik. <a href="https://doi.org/10.4230/LIPIcs.SoCG.2026.72">https://doi.org/10.4230/LIPIcs.SoCG.2026.72</a>'
  chicago: Leśkiewicz, Jakub, Bartosz Furmanek, Michał Lipiński, and Dmitriy Morozov.
    “Topological Simplification Guided by Forbidden Regions.” In <i>42nd International
    Symposium on Computational Geometry</i>, Vol. 367. Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik, 2026. <a href="https://doi.org/10.4230/LIPIcs.SoCG.2026.72">https://doi.org/10.4230/LIPIcs.SoCG.2026.72</a>.
  ieee: J. Leśkiewicz, B. Furmanek, M. Lipiński, and D. Morozov, “Topological simplification
    guided by forbidden regions,” in <i>42nd International Symposium on Computational
    Geometry</i>, New Brunswick, NJ, United States, 2026, vol. 367.
  ista: 'Leśkiewicz J, Furmanek B, Lipiński M, Morozov D. 2026. Topological simplification
    guided by forbidden regions. 42nd International Symposium on Computational Geometry.
    SoCG: Symposium on Computational Geometry, LIPIcs, vol. 367, 72:1-72:17.'
  mla: Leśkiewicz, Jakub, et al. “Topological Simplification Guided by Forbidden Regions.”
    <i>42nd International Symposium on Computational Geometry</i>, vol. 367, 72:1-72:17,
    Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2026, doi:<a href="https://doi.org/10.4230/LIPIcs.SoCG.2026.72">10.4230/LIPIcs.SoCG.2026.72</a>.
  short: J. Leśkiewicz, B. Furmanek, M. Lipiński, D. Morozov, in:, 42nd International
    Symposium on Computational Geometry, Schloss Dagstuhl - Leibniz-Zentrum für Informatik,
    2026.
conference:
  end_date: 2026-06-05
  location: New Brunswick, NJ, United States
  name: 'SoCG: Symposium on Computational Geometry'
  start_date: 2026-06-02
corr_author: '1'
das_tickbox: '0'
date_created: 2026-06-14T22:01:43Z
date_published: 2026-05-27T00:00:00Z
date_updated: 2026-06-22T07:45:36Z
day: '27'
ddc:
- '500'
department:
- _id: HeEd
doi: 10.4230/LIPIcs.SoCG.2026.72
ec_funded: 1
external_id:
  arxiv:
  - '2603.16416'
file:
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  checksum: 3be91c06fdf716c8735b6af64a09a921
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  creator: dernst
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  file_size: 2052749
  relation: main_file
  success: 1
file_date_updated: 2026-06-22T07:39:21Z
has_accepted_license: '1'
intvolume: '       367'
keyword:
- persistent homology
- topological simplification
- depth posets
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
project:
- _id: fc2ed2f7-9c52-11eb-aca3-c01059dda49c
  call_identifier: H2020
  grant_number: '101034413'
  name: 'IST-BRIDGE: International postdoctoral program'
publication: 42nd International Symposium on Computational Geometry
publication_identifier:
  eissn:
  - 1868-8969
  isbn:
  - '9783959774185'
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
quality_controlled: '1'
scopus_import: '1'
status: public
title: Topological simplification guided by forbidden regions
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: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 367
year: '2026'
...
---
OA_place: repository
OA_type: green
_id: '20980'
abstract:
- lang: eng
  text: 'Morse decompositions partition the flows in a vector field into equivalent
    structures. Given such a decomposition, one can define a further summary of its
    flow structure by what is called a connection matrix. These matrices, a generalization
    of Morse boundary operators from classical Morse theory, capture the connections
    made by the flows among the critical structures—such as attractors, repellers,
    and orbits—in a vector field. Recently, in the context of combinatorial dynamics,
    an efficient persistence-like algorithm to compute connection matrices has been
    proposed in Dey, Lipiński, Mrozek, and Slechta [SIAM J. Appl. Dyn. Syst., 23 (2024),
    pp. 81–97]. We show that, actually, the classical persistence algorithm with exhaustive
    reduction retrieves connection matrices, both simplifying the algorithm of Dey
    et al. and bringing the theory of persistence closer to combinatorial dynamical
    systems. We supplement this main result with an observation: the concept of persistence
    as defined for scalar fields naturally adapts to Morse decompositions whose Morse
    sets are filtered with a Lyapunov function. We conclude by presenting preliminary
    experimental results.'
acknowledgement: "This research was supported by NSF grants DMS-2301360 and CCF-2437030
  as well as from the European Union's Horizon 2020 research and innovation programme
  under Marie Sk\\lodowska-Curie grant 101034413.\r\n"
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Tamal K.
  full_name: Dey, Tamal K.
  last_name: Dey
- first_name: Andrew
  full_name: Haas, Andrew
  last_name: Haas
- first_name: Michał
  full_name: Lipiński, Michał
  id: dfffb474-4317-11ee-8f5c-fe3fc95a425e
  last_name: Lipiński
  orcid: 0000-0001-9789-9750
citation:
  ama: Dey TK, Haas A, Lipiński M. Computing a connection matrix and persistence efficiently
    from a morse decomposition. <i>SIAM Journal on Applied Dynamical Systems</i>.
    2026;25(1):108-130. doi:<a href="https://doi.org/10.1137/25m1739406">10.1137/25m1739406</a>
  apa: Dey, T. K., Haas, A., &#38; Lipiński, M. (2026). Computing a connection matrix
    and persistence efficiently from a morse decomposition. <i>SIAM Journal on Applied
    Dynamical Systems</i>. Society for Industrial &#38; Applied Mathematics. <a href="https://doi.org/10.1137/25m1739406">https://doi.org/10.1137/25m1739406</a>
  chicago: Dey, Tamal K., Andrew Haas, and Michał Lipiński. “Computing a Connection
    Matrix and Persistence Efficiently from a Morse Decomposition.” <i>SIAM Journal
    on Applied Dynamical Systems</i>. Society for Industrial &#38; Applied Mathematics,
    2026. <a href="https://doi.org/10.1137/25m1739406">https://doi.org/10.1137/25m1739406</a>.
  ieee: T. K. Dey, A. Haas, and M. Lipiński, “Computing a connection matrix and persistence
    efficiently from a morse decomposition,” <i>SIAM Journal on Applied Dynamical
    Systems</i>, vol. 25, no. 1. Society for Industrial &#38; Applied Mathematics,
    pp. 108–130, 2026.
  ista: Dey TK, Haas A, Lipiński M. 2026. Computing a connection matrix and persistence
    efficiently from a morse decomposition. SIAM Journal on Applied Dynamical Systems.
    25(1), 108–130.
  mla: Dey, Tamal K., et al. “Computing a Connection Matrix and Persistence Efficiently
    from a Morse Decomposition.” <i>SIAM Journal on Applied Dynamical Systems</i>,
    vol. 25, no. 1, Society for Industrial &#38; Applied Mathematics, 2026, pp. 108–30,
    doi:<a href="https://doi.org/10.1137/25m1739406">10.1137/25m1739406</a>.
  short: T.K. Dey, A. Haas, M. Lipiński, SIAM Journal on Applied Dynamical Systems
    25 (2026) 108–130.
date_created: 2026-01-12T11:17:06Z
date_published: 2026-01-01T00:00:00Z
date_updated: 2026-01-20T07:40:39Z
day: '01'
ddc:
- '510'
department:
- _id: HeEd
doi: 10.1137/25m1739406
ec_funded: 1
external_id:
  arxiv:
  - '2502.19369'
intvolume: '        25'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.48550/arXiv.2502.19369
month: '01'
oa: 1
oa_version: Preprint
page: 108-130
project:
- _id: fc2ed2f7-9c52-11eb-aca3-c01059dda49c
  call_identifier: H2020
  grant_number: '101034413'
  name: 'IST-BRIDGE: International postdoctoral program'
publication: SIAM Journal on Applied Dynamical Systems
publication_identifier:
  issn:
  - 1536-0040
publication_status: published
publisher: Society for Industrial & Applied Mathematics
quality_controlled: '1'
scopus_import: '1'
status: public
title: Computing a connection matrix and persistence efficiently from a morse decomposition
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 25
year: '2026'
...
---
OA_place: publisher
OA_type: hybrid
_id: '18580'
abstract:
- lang: eng
  text: Motivated by the study of recurrent orbits and dynamics within a Morse set
    of a Morse decomposition we introduce the concept of Morse predecomposition of
    an isolated invariant set within the setting of both combinatorial and classical
    dynamical systems. While Morse decomposition summarizes solely the gradient part
    of a dynamical system, the developed generalization extends to the recurrent component
    as well. In particular, a chain recurrent set, which is indecomposable in terms
    of Morse decomposition, can be represented more finely in the Morse predecomposition
    framework. This generalization is achieved by forgoing the poset structure inherent
    to Morse decomposition and relaxing the notion of connection between Morse sets
    (elements of Morse decomposition) in favor of what we term ’links’. We prove that
    a Morse decomposition is a special case of Morse predecomposition indexed by a
    poset. Additionally, we show how a Morse predecomposition may be condensed back
    to retrieve a Morse decomposition.
acknowledgement: 'M.L. acknowledge support by the Dioscuri program initiated by the
  Max Planck Society, jointly managed with the National Science Centre (Poland), and
  mutually funded by the Polish Ministry of Science and Higher Education and the German
  Federal Ministry of Education and Research. M.L. also acknowledges that this project
  has received funding from the European Union’s Horizon 2020 research and innovation
  programme under the Marie Skłodowska-Curie Grant Agreement No. 101034413. Research
  of M.M. is partially supported by the Polish National Science Center under Opus
  Grant No. 2019/35/B/ST1/00874. The work of K.M. was partially supported by the National
  Science Foundation under awards DMS-1839294 and HDR TRIPODS award CCF-1934924, DARPA
  contract HR0011-16-2-0033, National Institutes of Health award R01 GM126555, Air
  Force Office of Scientific Research under award numbers FA9550-23-1-0011, AWD00010853-MOD002
  and MURI FA9550-23-1-0400. K.M. was also supported by a grant from the Simons Foundation.
  Open access funding provided by Institute of Science and Technology (IST Austria). '
article_number: '5'
article_processing_charge: Yes (via OA deal)
article_type: original
arxiv: 1
author:
- first_name: Michał
  full_name: Lipiński, Michał
  id: dfffb474-4317-11ee-8f5c-fe3fc95a425e
  last_name: Lipiński
  orcid: 0000-0001-9789-9750
- first_name: Konstantin
  full_name: Mischaikow, Konstantin
  last_name: Mischaikow
- first_name: Marian
  full_name: Mrozek, Marian
  last_name: Mrozek
citation:
  ama: Lipiński M, Mischaikow K, Mrozek M. Morse predecomposition of an invariant
    set. <i>Qualitative Theory of Dynamical Systems</i>. 2025;24(1). doi:<a href="https://doi.org/10.1007/s12346-024-01144-3">10.1007/s12346-024-01144-3</a>
  apa: Lipiński, M., Mischaikow, K., &#38; Mrozek, M. (2025). Morse predecomposition
    of an invariant set. <i>Qualitative Theory of Dynamical Systems</i>. Springer
    Nature. <a href="https://doi.org/10.1007/s12346-024-01144-3">https://doi.org/10.1007/s12346-024-01144-3</a>
  chicago: Lipiński, Michał, Konstantin Mischaikow, and Marian Mrozek. “Morse Predecomposition
    of an Invariant Set.” <i>Qualitative Theory of Dynamical Systems</i>. Springer
    Nature, 2025. <a href="https://doi.org/10.1007/s12346-024-01144-3">https://doi.org/10.1007/s12346-024-01144-3</a>.
  ieee: M. Lipiński, K. Mischaikow, and M. Mrozek, “Morse predecomposition of an invariant
    set,” <i>Qualitative Theory of Dynamical Systems</i>, vol. 24, no. 1. Springer
    Nature, 2025.
  ista: Lipiński M, Mischaikow K, Mrozek M. 2025. Morse predecomposition of an invariant
    set. Qualitative Theory of Dynamical Systems. 24(1), 5.
  mla: Lipiński, Michał, et al. “Morse Predecomposition of an Invariant Set.” <i>Qualitative
    Theory of Dynamical Systems</i>, vol. 24, no. 1, 5, Springer Nature, 2025, doi:<a
    href="https://doi.org/10.1007/s12346-024-01144-3">10.1007/s12346-024-01144-3</a>.
  short: M. Lipiński, K. Mischaikow, M. Mrozek, Qualitative Theory of Dynamical Systems
    24 (2025).
corr_author: '1'
date_created: 2024-11-24T23:01:47Z
date_published: 2025-02-01T00:00:00Z
date_updated: 2025-04-14T07:54:56Z
day: '01'
ddc:
- '514'
- '510'
department:
- _id: UlWa
doi: 10.1007/s12346-024-01144-3
ec_funded: 1
external_id:
  arxiv:
  - '2312.08013'
  isi:
  - '001356000500005'
file:
- access_level: open_access
  checksum: 73309a57cc798d696caa57b6aa1467d8
  content_type: application/pdf
  creator: mlipinsk
  date_created: 2024-11-28T06:52:38Z
  date_updated: 2024-11-28T06:52:38Z
  file_id: '18595'
  file_name: 2025_predecomposition.pdf
  file_size: 1483668
  relation: main_file
  success: 1
file_date_updated: 2024-11-28T06:52:38Z
has_accepted_license: '1'
intvolume: '        24'
isi: 1
issue: '1'
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
project:
- _id: fc2ed2f7-9c52-11eb-aca3-c01059dda49c
  call_identifier: H2020
  grant_number: '101034413'
  name: 'IST-BRIDGE: International postdoctoral program'
publication: Qualitative Theory of Dynamical Systems
publication_identifier:
  eissn:
  - 1662-3592
  issn:
  - 1575-5460
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Morse predecomposition of an invariant set
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  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
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  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 24
year: '2025'
...
