---
_id: '15012'
abstract:
- lang: eng
  text: We solve a problem of Dujmović and Wood (2007) by showing that a complete
    convex geometric graph on n vertices cannot be decomposed into fewer than n-1
    star-forests, each consisting of noncrossing edges. This bound is clearly tight.
    We also discuss similar questions for abstract graphs.
acknowledgement: János Pach’s Research partially supported by European Research Council
  (ERC), grant “GeoScape” No. 882971 and by the Hungarian Science Foundation (NKFIH),
  grant K-131529. Work by Morteza Saghafian is partially supported by the European
  Research Council (ERC), grant No. 788183, and by the Wittgenstein Prize, Austrian
  Science Fund (FWF), grant No. Z 342-N31.
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: János
  full_name: Pach, János
  id: E62E3130-B088-11EA-B919-BF823C25FEA4
  last_name: Pach
- first_name: Morteza
  full_name: Saghafian, Morteza
  id: f86f7148-b140-11ec-9577-95435b8df824
  last_name: Saghafian
- first_name: Patrick
  full_name: Schnider, Patrick
  last_name: Schnider
citation:
  ama: 'Pach J, Saghafian M, Schnider P. Decomposition of geometric graphs into star-forests.
    In: <i>31st International Symposium on Graph Drawing and Network Visualization</i>.
    Vol 14465. Springer Nature; 2024:339-346. doi:<a href="https://doi.org/10.1007/978-3-031-49272-3_23">10.1007/978-3-031-49272-3_23</a>'
  apa: 'Pach, J., Saghafian, M., &#38; Schnider, P. (2024). Decomposition of geometric
    graphs into star-forests. In <i>31st International Symposium on Graph Drawing
    and Network Visualization</i> (Vol. 14465, pp. 339–346). Isola delle Femmine,
    Palermo, Italy: Springer Nature. <a href="https://doi.org/10.1007/978-3-031-49272-3_23">https://doi.org/10.1007/978-3-031-49272-3_23</a>'
  chicago: Pach, János, Morteza Saghafian, and Patrick Schnider. “Decomposition of Geometric
    Graphs into Star-Forests.” In <i>31st International Symposium on Graph Drawing
    and Network Visualization</i>, 14465:339–46. Springer Nature, 2024. <a href="https://doi.org/10.1007/978-3-031-49272-3_23">https://doi.org/10.1007/978-3-031-49272-3_23</a>.
  ieee: J. Pach, M. Saghafian, and P. Schnider, “Decomposition of geometric graphs
    into star-forests,” in <i>31st International Symposium on Graph Drawing and Network
    Visualization</i>, Isola delle Femmine, Palermo, Italy, 2024, vol. 14465, pp.
    339–346.
  ista: 'Pach J, Saghafian M, Schnider P. 2024. Decomposition of geometric graphs
    into star-forests. 31st International Symposium on Graph Drawing and Network Visualization.
    GD: Graph Drawing and Network Visualization, LNCS, vol. 14465, 339–346.'
  mla: Pach, János, et al. “Decomposition of Geometric Graphs into Star-Forests.”
    <i>31st International Symposium on Graph Drawing and Network Visualization</i>,
    vol. 14465, Springer Nature, 2024, pp. 339–46, doi:<a href="https://doi.org/10.1007/978-3-031-49272-3_23">10.1007/978-3-031-49272-3_23</a>.
  short: J. Pach, M. Saghafian, P. Schnider, in:, 31st International Symposium on
    Graph Drawing and Network Visualization, Springer Nature, 2024, pp. 339–346.
conference:
  end_date: 2023-09-22
  location: Isola delle Femmine, Palermo, Italy
  name: 'GD: Graph Drawing and Network Visualization'
  start_date: 2023-09-20
date_created: 2024-02-18T23:01:03Z
date_published: 2024-01-01T00:00:00Z
date_updated: 2024-02-20T09:13:07Z
day: '01'
department:
- _id: HeEd
doi: 10.1007/978-3-031-49272-3_23
ec_funded: 1
external_id:
  arxiv:
  - '2306.13201'
intvolume: '     14465'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.48550/arXiv.2306.13201
month: '01'
oa: 1
oa_version: Preprint
page: 339-346
project:
- _id: 266A2E9E-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '788183'
  name: Alpha Shape Theory Extended
- _id: 268116B8-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: Z00342
  name: The Wittgenstein Prize
publication: 31st International Symposium on Graph Drawing and Network Visualization
publication_identifier:
  eissn:
  - '16113349'
  isbn:
  - '9783031492716'
  issn:
  - '03029743'
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Decomposition of geometric graphs into star-forests
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 14465
year: '2024'
...
---
_id: '14345'
abstract:
- lang: eng
  text: For a locally finite set in R2, the order-k Brillouin tessellations form an
    infinite sequence of convex face-to-face tilings of the plane. If the set is coarsely
    dense and generic, then the corresponding infinite sequences of minimum and maximum
    angles are both monotonic in k. As an example, a stationary Poisson point process
    in R2  is locally finite, coarsely dense, and generic with probability one. For
    such a set, the distributions of angles in the Voronoi tessellations, Delaunay
    mosaics, and Brillouin tessellations are independent of the order and can be derived
    from the formula for angles in order-1 Delaunay mosaics given by Miles (Math.
    Biosci. 6, 85–127 (1970)).
acknowledgement: Work by all authors but A. Garber is supported by the European Research
  Council (ERC), Grant No. 788183, by the Wittgenstein Prize, Austrian Science Fund
  (FWF), Grant No. Z 342-N31, and by the DFG Collaborative Research Center TRR 109,
  Austrian Science Fund (FWF), Grant No. I 02979-N35. Work by A. Garber is partially
  supported by the Alexander von Humboldt Foundation.
article_processing_charge: Yes (via OA deal)
article_type: original
arxiv: 1
author:
- first_name: Herbert
  full_name: Edelsbrunner, Herbert
  id: 3FB178DA-F248-11E8-B48F-1D18A9856A87
  last_name: Edelsbrunner
  orcid: 0000-0002-9823-6833
- first_name: Alexey
  full_name: Garber, Alexey
  last_name: Garber
- first_name: Mohadese
  full_name: Ghafari, Mohadese
  last_name: Ghafari
- first_name: Teresa
  full_name: Heiss, Teresa
  id: 4879BB4E-F248-11E8-B48F-1D18A9856A87
  last_name: Heiss
  orcid: 0000-0002-1780-2689
- first_name: Morteza
  full_name: Saghafian, Morteza
  id: f86f7148-b140-11ec-9577-95435b8df824
  last_name: Saghafian
citation:
  ama: Edelsbrunner H, Garber A, Ghafari M, Heiss T, Saghafian M. On angles in higher
    order Brillouin tessellations and related tilings in the plane. <i>Discrete and
    Computational Geometry</i>. 2023. doi:<a href="https://doi.org/10.1007/s00454-023-00566-1">10.1007/s00454-023-00566-1</a>
  apa: Edelsbrunner, H., Garber, A., Ghafari, M., Heiss, T., &#38; Saghafian, M. (2023).
    On angles in higher order Brillouin tessellations and related tilings in the plane.
    <i>Discrete and Computational Geometry</i>. Springer Nature. <a href="https://doi.org/10.1007/s00454-023-00566-1">https://doi.org/10.1007/s00454-023-00566-1</a>
  chicago: Edelsbrunner, Herbert, Alexey Garber, Mohadese Ghafari, Teresa Heiss, and
    Morteza Saghafian. “On Angles in Higher Order Brillouin Tessellations and Related
    Tilings in the Plane.” <i>Discrete and Computational Geometry</i>. Springer Nature,
    2023. <a href="https://doi.org/10.1007/s00454-023-00566-1">https://doi.org/10.1007/s00454-023-00566-1</a>.
  ieee: H. Edelsbrunner, A. Garber, M. Ghafari, T. Heiss, and M. Saghafian, “On angles
    in higher order Brillouin tessellations and related tilings in the plane,” <i>Discrete
    and Computational Geometry</i>. Springer Nature, 2023.
  ista: Edelsbrunner H, Garber A, Ghafari M, Heiss T, Saghafian M. 2023. On angles
    in higher order Brillouin tessellations and related tilings in the plane. Discrete
    and Computational Geometry.
  mla: Edelsbrunner, Herbert, et al. “On Angles in Higher Order Brillouin Tessellations
    and Related Tilings in the Plane.” <i>Discrete and Computational Geometry</i>,
    Springer Nature, 2023, doi:<a href="https://doi.org/10.1007/s00454-023-00566-1">10.1007/s00454-023-00566-1</a>.
  short: H. Edelsbrunner, A. Garber, M. Ghafari, T. Heiss, M. Saghafian, Discrete
    and Computational Geometry (2023).
date_created: 2023-09-17T22:01:10Z
date_published: 2023-09-07T00:00:00Z
date_updated: 2023-12-13T12:25:06Z
day: '07'
department:
- _id: HeEd
doi: 10.1007/s00454-023-00566-1
ec_funded: 1
external_id:
  arxiv:
  - '2204.01076'
  isi:
  - '001060727600004'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1007/s00454-023-00566-1
month: '09'
oa: 1
oa_version: Published Version
project:
- _id: 266A2E9E-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '788183'
  name: Alpha Shape Theory Extended
- _id: 268116B8-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: Z00342
  name: The Wittgenstein Prize
- _id: 2561EBF4-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: I02979-N35
  name: Persistence and stability of geometric complexes
publication: Discrete and Computational Geometry
publication_identifier:
  eissn:
  - 1432-0444
  issn:
  - 0179-5376
publication_status: epub_ahead
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: On angles in higher order Brillouin tessellations and related tilings in the
  plane
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2023'
...
---
_id: '13182'
abstract:
- lang: eng
  text: "We characterize critical points of 1-dimensional maps paired in persistent
    homology\r\ngeometrically and this way get elementary proofs of theorems about
    the symmetry\r\nof persistence diagrams and the variation of such maps. In particular,
    we identify\r\nbranching points and endpoints of networks as the sole source of
    asymmetry and\r\nrelate the cycle basis in persistent homology with a version
    of the stable marriage\r\nproblem. Our analysis provides the foundations of fast
    algorithms for maintaining a\r\ncollection of sorted lists together with its persistence
    diagram."
acknowledgement: Open access funding provided by Austrian Science Fund (FWF). This
  project has received funding from the European Research Council (ERC) under the
  European Union’s Horizon 2020 research and innovation programme, grant no. 788183,
  from the Wittgenstein Prize, Austrian Science Fund (FWF), Grant No. Z 342-N31, and
  from the DFG Collaborative Research Center TRR 109, ‘Discretization in Geometry
  and Dynamics’, Austrian Science Fund (FWF), Grant No. I 02979-N35. The authors of
  this paper thank anonymous reviewers for their constructive criticism and Monika
  Henzinger for detailed comments on an earlier version of this paper.
article_processing_charge: Yes (via OA deal)
article_type: original
author:
- first_name: Ranita
  full_name: Biswas, Ranita
  id: 3C2B033E-F248-11E8-B48F-1D18A9856A87
  last_name: Biswas
  orcid: 0000-0002-5372-7890
- first_name: Sebastiano
  full_name: Cultrera Di Montesano, Sebastiano
  id: 34D2A09C-F248-11E8-B48F-1D18A9856A87
  last_name: Cultrera Di Montesano
  orcid: 0000-0001-6249-0832
- first_name: Herbert
  full_name: Edelsbrunner, Herbert
  id: 3FB178DA-F248-11E8-B48F-1D18A9856A87
  last_name: Edelsbrunner
  orcid: 0000-0002-9823-6833
- first_name: Morteza
  full_name: Saghafian, Morteza
  id: f86f7148-b140-11ec-9577-95435b8df824
  last_name: Saghafian
citation:
  ama: Biswas R, Cultrera di Montesano S, Edelsbrunner H, Saghafian M. Geometric characterization
    of the persistence of 1D maps. <i>Journal of Applied and Computational Topology</i>.
    2023. doi:<a href="https://doi.org/10.1007/s41468-023-00126-9">10.1007/s41468-023-00126-9</a>
  apa: Biswas, R., Cultrera di Montesano, S., Edelsbrunner, H., &#38; Saghafian, M.
    (2023). Geometric characterization of the persistence of 1D maps. <i>Journal of
    Applied and Computational Topology</i>. Springer Nature. <a href="https://doi.org/10.1007/s41468-023-00126-9">https://doi.org/10.1007/s41468-023-00126-9</a>
  chicago: Biswas, Ranita, Sebastiano Cultrera di Montesano, Herbert Edelsbrunner,
    and Morteza Saghafian. “Geometric Characterization of the Persistence of 1D Maps.”
    <i>Journal of Applied and Computational Topology</i>. Springer Nature, 2023. <a
    href="https://doi.org/10.1007/s41468-023-00126-9">https://doi.org/10.1007/s41468-023-00126-9</a>.
  ieee: R. Biswas, S. Cultrera di Montesano, H. Edelsbrunner, and M. Saghafian, “Geometric
    characterization of the persistence of 1D maps,” <i>Journal of Applied and Computational
    Topology</i>. Springer Nature, 2023.
  ista: Biswas R, Cultrera di Montesano S, Edelsbrunner H, Saghafian M. 2023. Geometric
    characterization of the persistence of 1D maps. Journal of Applied and Computational
    Topology.
  mla: Biswas, Ranita, et al. “Geometric Characterization of the Persistence of 1D
    Maps.” <i>Journal of Applied and Computational Topology</i>, Springer Nature,
    2023, doi:<a href="https://doi.org/10.1007/s41468-023-00126-9">10.1007/s41468-023-00126-9</a>.
  short: R. Biswas, S. Cultrera di Montesano, H. Edelsbrunner, M. Saghafian, Journal
    of Applied and Computational Topology (2023).
date_created: 2023-07-02T22:00:44Z
date_published: 2023-06-17T00:00:00Z
date_updated: 2023-10-18T08:13:10Z
day: '17'
ddc:
- '000'
department:
- _id: HeEd
doi: 10.1007/s41468-023-00126-9
ec_funded: 1
file:
- access_level: open_access
  checksum: 697249d5d1c61dea4410b9f021b70fce
  content_type: application/pdf
  creator: alisjak
  date_created: 2023-07-03T09:41:05Z
  date_updated: 2023-07-03T09:41:05Z
  file_id: '13185'
  file_name: 2023_Journal of Applied and Computational Topology_Biswas.pdf
  file_size: 487355
  relation: main_file
  success: 1
file_date_updated: 2023-07-03T09:41:05Z
has_accepted_license: '1'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
project:
- _id: 266A2E9E-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '788183'
  name: Alpha Shape Theory Extended
- _id: 0aa4bc98-070f-11eb-9043-e6fff9c6a316
  grant_number: I4887
  name: Discretization in Geometry and Dynamics
- _id: 268116B8-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: Z00342
  name: The Wittgenstein Prize
publication: Journal of Applied and Computational Topology
publication_identifier:
  eissn:
  - 2367-1734
  issn:
  - 2367-1726
publication_status: epub_ahead
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Geometric characterization of the persistence of 1D maps
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: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2023'
...
---
_id: '11658'
abstract:
- lang: eng
  text: The depth of a cell in an arrangement of n (non-vertical) great-spheres in
    Sd is the number of great-spheres that pass above the cell. We prove Euler-type
    relations, which imply extensions of the classic Dehn–Sommerville relations for
    convex polytopes to sublevel sets of the depth function, and we use the relations
    to extend the expressions for the number of faces of neighborly polytopes to the
    number of cells of levels in neighborly arrangements.
acknowledgement: This project has received funding from the European Research Council
  (ERC) under the European Union’s Horizon 2020 research and innovation programme,
  grant no. 788183, from the Wittgenstein Prize, Austrian Science Fund (FWF), grant
  no. Z 342-N31, and from the DFG Collaborative Research Center TRR 109, ‘Discretization
  in Geometry and Dynamics’, Austrian Science Fund (FWF), grant no. I 02979-N35.
article_processing_charge: No
author:
- first_name: Ranita
  full_name: Biswas, Ranita
  id: 3C2B033E-F248-11E8-B48F-1D18A9856A87
  last_name: Biswas
  orcid: 0000-0002-5372-7890
- first_name: Sebastiano
  full_name: Cultrera di Montesano, Sebastiano
  id: 34D2A09C-F248-11E8-B48F-1D18A9856A87
  last_name: Cultrera di Montesano
  orcid: 0000-0001-6249-0832
- first_name: Herbert
  full_name: Edelsbrunner, Herbert
  id: 3FB178DA-F248-11E8-B48F-1D18A9856A87
  last_name: Edelsbrunner
  orcid: 0000-0002-9823-6833
- first_name: Morteza
  full_name: Saghafian, Morteza
  id: f86f7148-b140-11ec-9577-95435b8df824
  last_name: Saghafian
citation:
  ama: 'Biswas R, Cultrera di Montesano S, Edelsbrunner H, Saghafian M. Depth in arrangements:
    Dehn–Sommerville–Euler relations with applications. <i>Leibniz International Proceedings
    on Mathematics</i>.'
  apa: 'Biswas, R., Cultrera di Montesano, S., Edelsbrunner, H., &#38; Saghafian,
    M. (n.d.). Depth in arrangements: Dehn–Sommerville–Euler relations with applications.
    <i>Leibniz International Proceedings on Mathematics</i>. Schloss Dagstuhl - Leibniz
    Zentrum für Informatik.'
  chicago: 'Biswas, Ranita, Sebastiano Cultrera di Montesano, Herbert Edelsbrunner,
    and Morteza Saghafian. “Depth in Arrangements: Dehn–Sommerville–Euler Relations
    with Applications.” <i>Leibniz International Proceedings on Mathematics</i>. Schloss
    Dagstuhl - Leibniz Zentrum für Informatik, n.d.'
  ieee: 'R. Biswas, S. Cultrera di Montesano, H. Edelsbrunner, and M. Saghafian, “Depth
    in arrangements: Dehn–Sommerville–Euler relations with applications,” <i>Leibniz
    International Proceedings on Mathematics</i>. Schloss Dagstuhl - Leibniz Zentrum
    für Informatik.'
  ista: 'Biswas R, Cultrera di Montesano S, Edelsbrunner H, Saghafian M. Depth in
    arrangements: Dehn–Sommerville–Euler relations with applications. Leibniz International
    Proceedings on Mathematics.'
  mla: 'Biswas, Ranita, et al. “Depth in Arrangements: Dehn–Sommerville–Euler Relations
    with Applications.” <i>Leibniz International Proceedings on Mathematics</i>, Schloss
    Dagstuhl - Leibniz Zentrum für Informatik.'
  short: R. Biswas, S. Cultrera di Montesano, H. Edelsbrunner, M. Saghafian, Leibniz
    International Proceedings on Mathematics (n.d.).
date_created: 2022-07-27T09:27:34Z
date_published: 2022-07-27T00:00:00Z
date_updated: 2022-07-28T07:57:48Z
day: '27'
ddc:
- '510'
department:
- _id: GradSch
- _id: HeEd
ec_funded: 1
file:
- access_level: open_access
  checksum: b2f511e8b1cae5f1892b0cdec341acac
  content_type: application/pdf
  creator: scultrer
  date_created: 2022-07-27T09:25:53Z
  date_updated: 2022-07-27T09:25:53Z
  file_id: '11659'
  file_name: D-S-E.pdf
  file_size: 639266
  relation: main_file
file_date_updated: 2022-07-27T09:25:53Z
has_accepted_license: '1'
language:
- iso: eng
month: '07'
oa: 1
oa_version: Submitted Version
project:
- _id: 266A2E9E-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '788183'
  name: Alpha Shape Theory Extended
- _id: 268116B8-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: Z00342
  name: The Wittgenstein Prize
- _id: 2561EBF4-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: I02979-N35
  name: Persistence and stability of geometric complexes
publication: Leibniz International Proceedings on Mathematics
publication_status: submitted
publisher: Schloss Dagstuhl - Leibniz Zentrum für Informatik
quality_controlled: '1'
status: public
title: 'Depth in arrangements: Dehn–Sommerville–Euler relations with applications'
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: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2022'
...
