---
_id: '13974'
abstract:
- lang: eng
  text: The Tverberg theorem is one of the cornerstones of discrete geometry. It states
    that, given a set X of at least (d+1)(r−1)+1 points in Rd, one can find a partition
    X=X1∪⋯∪Xr of X, such that the convex hulls of the Xi, i=1,…,r, all share a common
    point. In this paper, we prove a trengthening of this theorem that guarantees
    a partition which, in addition to the above, has the property that the boundaries
    of full-dimensional convex hulls have pairwise nonempty intersections. Possible
    generalizations and algorithmic aspects are also discussed. As a concrete application,
    we show that any n points in the plane in general position span ⌊n/3⌋ vertex-disjoint
    triangles that are pairwise crossing, meaning that their boundaries have pairwise
    nonempty intersections; this number is clearly best possible. A previous result
    of Álvarez-Rebollar et al. guarantees ⌊n/6⌋pairwise crossing triangles. Our result
    generalizes to a result about simplices in Rd, d≥2.
acknowledgement: "Part of the research leading to this paper was done during the 16th
  Gremo Workshop on Open Problems (GWOP), Waltensburg, Switzerland, June 12–16, 2018.
  We thank Patrick Schnider for suggesting the problem, and Stefan Felsner, Malte
  Milatz, and Emo Welzl for fruitful discussions during the workshop. We also thank
  Stefan Felsner and Manfred Scheucher for finding, communicating the example from
  Sect. 3.3, and the kind permission to include their visualization of the point set.
  We thank Dömötör Pálvölgyi, the SoCG reviewers, and DCG reviewers for various helpful
  comments.\r\nR. Fulek gratefully acknowledges support from Austrian Science Fund
  (FWF), Project  M2281-N35. A. Kupavskii was supported by the Advanced Postdoc.Mobility
  Grant no. P300P2_177839 of the Swiss National Science Foundation. Research by P.
  Valtr was supported by the Grant no. 18-19158 S of the Czech Science Foundation
  (GAČR)."
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Radoslav
  full_name: Fulek, Radoslav
  id: 39F3FFE4-F248-11E8-B48F-1D18A9856A87
  last_name: Fulek
  orcid: 0000-0001-8485-1774
- first_name: Bernd
  full_name: Gärtner, Bernd
  last_name: Gärtner
- first_name: Andrey
  full_name: Kupavskii, Andrey
  last_name: Kupavskii
- first_name: Pavel
  full_name: Valtr, Pavel
  last_name: Valtr
- first_name: Uli
  full_name: Wagner, Uli
  id: 36690CA2-F248-11E8-B48F-1D18A9856A87
  last_name: Wagner
  orcid: 0000-0002-1494-0568
citation:
  ama: Fulek R, Gärtner B, Kupavskii A, Valtr P, Wagner U. The crossing Tverberg theorem.
    <i>Discrete and Computational Geometry</i>. 2023. doi:<a href="https://doi.org/10.1007/s00454-023-00532-x">10.1007/s00454-023-00532-x</a>
  apa: Fulek, R., Gärtner, B., Kupavskii, A., Valtr, P., &#38; Wagner, U. (2023).
    The crossing Tverberg theorem. <i>Discrete and Computational Geometry</i>. Springer
    Nature. <a href="https://doi.org/10.1007/s00454-023-00532-x">https://doi.org/10.1007/s00454-023-00532-x</a>
  chicago: Fulek, Radoslav, Bernd Gärtner, Andrey Kupavskii, Pavel Valtr, and Uli
    Wagner. “The Crossing Tverberg Theorem.” <i>Discrete and Computational Geometry</i>.
    Springer Nature, 2023. <a href="https://doi.org/10.1007/s00454-023-00532-x">https://doi.org/10.1007/s00454-023-00532-x</a>.
  ieee: R. Fulek, B. Gärtner, A. Kupavskii, P. Valtr, and U. Wagner, “The crossing
    Tverberg theorem,” <i>Discrete and Computational Geometry</i>. Springer Nature,
    2023.
  ista: Fulek R, Gärtner B, Kupavskii A, Valtr P, Wagner U. 2023. The crossing Tverberg
    theorem. Discrete and Computational Geometry.
  mla: Fulek, Radoslav, et al. “The Crossing Tverberg Theorem.” <i>Discrete and Computational
    Geometry</i>, Springer Nature, 2023, doi:<a href="https://doi.org/10.1007/s00454-023-00532-x">10.1007/s00454-023-00532-x</a>.
  short: R. Fulek, B. Gärtner, A. Kupavskii, P. Valtr, U. Wagner, Discrete and Computational
    Geometry (2023).
date_created: 2023-08-06T22:01:12Z
date_published: 2023-07-27T00:00:00Z
date_updated: 2023-12-13T12:03:35Z
day: '27'
department:
- _id: UlWa
doi: 10.1007/s00454-023-00532-x
external_id:
  arxiv:
  - '1812.04911'
  isi:
  - '001038546500001'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.48550/arXiv.1812.04911
month: '07'
oa: 1
oa_version: Preprint
project:
- _id: 261FA626-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: M02281
  name: Eliminating intersections in drawings of graphs
publication: Discrete and Computational Geometry
publication_identifier:
  eissn:
  - 1432-0444
  issn:
  - 0179-5376
publication_status: epub_ahead
publisher: Springer Nature
quality_controlled: '1'
related_material:
  record:
  - id: '6647'
    relation: earlier_version
    status: public
scopus_import: '1'
status: public
title: The crossing Tverberg theorem
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2023'
...
---
_id: '11593'
abstract:
- lang: eng
  text: 'A drawing of a graph on a surface is independently even if every pair of
    nonadjacent edges in the drawing crosses an even number of times. The Z2 -genus
    of a graph G is the minimum g such that G has an independently even drawing on
    the orientable surface of genus g. An unpublished result by Robertson and Seymour
    implies that for every t, every graph of sufficiently large genus contains as
    a minor a projective t×t grid or one of the following so-called t -Kuratowski
    graphs: K3,t, or t copies of K5 or K3,3 sharing at most two common vertices. We
    show that the Z2-genus of graphs in these families is unbounded in t; in fact,
    equal to their genus. Together, this implies that the genus of a graph is bounded
    from above by a function of its Z2-genus, solving a problem posed by Schaefer
    and Štefankovič, and giving an approximate version of the Hanani–Tutte theorem
    on orientable surfaces. We also obtain an analogous result for Euler genus and
    Euler Z2-genus of graphs.'
acknowledgement: "We thank Zdeněk Dvořák, Xavier Goaoc, and Pavel Paták for helpful
  discussions. We also thank Bojan Mohar, Paul Seymour, Gelasio Salazar, Jim Geelen,
  and John Maharry for information about their unpublished results related to Conjecture
  3.1. Finally we thank the reviewers for corrections and suggestions for improving
  the presentation.\r\nSupported by Austrian Science Fund (FWF): M2281-N35. Supported
  by project 19-04113Y of the Czech Science Foundation (GAČR), by the Czech-French
  collaboration project EMBEDS II (CZ: 7AMB17FR029, FR: 38087RM), and by Charles University
  project UNCE/SCI/004."
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Radoslav
  full_name: Fulek, Radoslav
  id: 39F3FFE4-F248-11E8-B48F-1D18A9856A87
  last_name: Fulek
  orcid: 0000-0001-8485-1774
- first_name: Jan
  full_name: Kynčl, Jan
  last_name: Kynčl
citation:
  ama: Fulek R, Kynčl J. The Z2-Genus of Kuratowski minors. <i>Discrete and Computational
    Geometry</i>. 2022;68:425-447. doi:<a href="https://doi.org/10.1007/s00454-022-00412-w">10.1007/s00454-022-00412-w</a>
  apa: Fulek, R., &#38; Kynčl, J. (2022). The Z2-Genus of Kuratowski minors. <i>Discrete
    and Computational Geometry</i>. Springer Nature. <a href="https://doi.org/10.1007/s00454-022-00412-w">https://doi.org/10.1007/s00454-022-00412-w</a>
  chicago: Fulek, Radoslav, and Jan Kynčl. “The Z2-Genus of Kuratowski Minors.” <i>Discrete
    and Computational Geometry</i>. Springer Nature, 2022. <a href="https://doi.org/10.1007/s00454-022-00412-w">https://doi.org/10.1007/s00454-022-00412-w</a>.
  ieee: R. Fulek and J. Kynčl, “The Z2-Genus of Kuratowski minors,” <i>Discrete and
    Computational Geometry</i>, vol. 68. Springer Nature, pp. 425–447, 2022.
  ista: Fulek R, Kynčl J. 2022. The Z2-Genus of Kuratowski minors. Discrete and Computational
    Geometry. 68, 425–447.
  mla: Fulek, Radoslav, and Jan Kynčl. “The Z2-Genus of Kuratowski Minors.” <i>Discrete
    and Computational Geometry</i>, vol. 68, Springer Nature, 2022, pp. 425–47, doi:<a
    href="https://doi.org/10.1007/s00454-022-00412-w">10.1007/s00454-022-00412-w</a>.
  short: R. Fulek, J. Kynčl, Discrete and Computational Geometry 68 (2022) 425–447.
date_created: 2022-07-17T22:01:56Z
date_published: 2022-09-01T00:00:00Z
date_updated: 2023-08-14T12:43:52Z
day: '01'
department:
- _id: UlWa
doi: 10.1007/s00454-022-00412-w
external_id:
  arxiv:
  - '1803.05085'
  isi:
  - '000825014500001'
intvolume: '        68'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1803.05085
month: '09'
oa: 1
oa_version: Preprint
page: 425-447
project:
- _id: 261FA626-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: M02281
  name: Eliminating intersections in drawings of graphs
publication: Discrete and Computational Geometry
publication_identifier:
  eissn:
  - 1432-0444
  issn:
  - 0179-5376
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
related_material:
  record:
  - id: '186'
    relation: earlier_version
    status: public
scopus_import: '1'
status: public
title: The Z2-Genus of Kuratowski minors
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 68
year: '2022'
...
---
_id: '5857'
abstract:
- lang: eng
  text: 'A thrackle is a graph drawn in the plane so that every pair of its edges
    meet exactly once: either at a common end vertex or in a proper crossing. We prove
    that any thrackle of n vertices has at most 1.3984n edges. Quasi-thrackles are
    defined similarly, except that every pair of edges that do not share a vertex
    are allowed to cross an odd number of times. It is also shown that the maximum
    number of edges of a quasi-thrackle on n vertices is [Formula presented](n−1),
    and that this bound is best possible for infinitely many values of n.'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Radoslav
  full_name: Fulek, Radoslav
  id: 39F3FFE4-F248-11E8-B48F-1D18A9856A87
  last_name: Fulek
  orcid: 0000-0001-8485-1774
- first_name: János
  full_name: Pach, János
  last_name: Pach
citation:
  ama: 'Fulek R, Pach J. Thrackles: An improved upper bound. <i>Discrete Applied Mathematics</i>.
    2019;259(4):266-231. doi:<a href="https://doi.org/10.1016/j.dam.2018.12.025">10.1016/j.dam.2018.12.025</a>'
  apa: 'Fulek, R., &#38; Pach, J. (2019). Thrackles: An improved upper bound. <i>Discrete
    Applied Mathematics</i>. Elsevier. <a href="https://doi.org/10.1016/j.dam.2018.12.025">https://doi.org/10.1016/j.dam.2018.12.025</a>'
  chicago: 'Fulek, Radoslav, and János Pach. “Thrackles: An Improved Upper Bound.”
    <i>Discrete Applied Mathematics</i>. Elsevier, 2019. <a href="https://doi.org/10.1016/j.dam.2018.12.025">https://doi.org/10.1016/j.dam.2018.12.025</a>.'
  ieee: 'R. Fulek and J. Pach, “Thrackles: An improved upper bound,” <i>Discrete Applied
    Mathematics</i>, vol. 259, no. 4. Elsevier, pp. 266–231, 2019.'
  ista: 'Fulek R, Pach J. 2019. Thrackles: An improved upper bound. Discrete Applied
    Mathematics. 259(4), 266–231.'
  mla: 'Fulek, Radoslav, and János Pach. “Thrackles: An Improved Upper Bound.” <i>Discrete
    Applied Mathematics</i>, vol. 259, no. 4, Elsevier, 2019, pp. 266–231, doi:<a
    href="https://doi.org/10.1016/j.dam.2018.12.025">10.1016/j.dam.2018.12.025</a>.'
  short: R. Fulek, J. Pach, Discrete Applied Mathematics 259 (2019) 266–231.
date_created: 2019-01-20T22:59:17Z
date_published: 2019-04-30T00:00:00Z
date_updated: 2023-08-24T14:39:33Z
day: '30'
department:
- _id: UlWa
doi: 10.1016/j.dam.2018.12.025
external_id:
  arxiv:
  - '1708.08037'
  isi:
  - '000466061100020'
intvolume: '       259'
isi: 1
issue: '4'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1708.08037
month: '04'
oa: 1
oa_version: Preprint
page: 266-231
project:
- _id: 261FA626-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: M02281
  name: Eliminating intersections in drawings of graphs
publication: Discrete Applied Mathematics
publication_identifier:
  issn:
  - 0166218X
publication_status: published
publisher: Elsevier
quality_controlled: '1'
related_material:
  record:
  - id: '433'
    relation: earlier_version
    status: public
scopus_import: '1'
status: public
title: 'Thrackles: An improved upper bound'
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 259
year: '2019'
...
---
_id: '6647'
abstract:
- lang: eng
  text: The Tverberg theorem is one of the cornerstones of discrete geometry. It states
    that, given a set X of at least (d+1)(r-1)+1 points in R^d, one can find a partition
    X=X_1 cup ... cup X_r of X, such that the convex hulls of the X_i, i=1,...,r,
    all share a common point. In this paper, we prove a strengthening of this theorem
    that guarantees a partition which, in addition to the above, has the property
    that the boundaries of full-dimensional convex hulls have pairwise nonempty intersections.
    Possible generalizations and algorithmic aspects are also discussed. As a concrete
    application, we show that any n points in the plane in general position span floor[n/3]
    vertex-disjoint triangles that are pairwise crossing, meaning that their boundaries
    have pairwise nonempty intersections; this number is clearly best possible. A
    previous result of Alvarez-Rebollar et al. guarantees floor[n/6] pairwise crossing
    triangles. Our result generalizes to a result about simplices in R^d,d >=2.
alternative_title:
- LIPIcs
arxiv: 1
author:
- first_name: Radoslav
  full_name: Fulek, Radoslav
  id: 39F3FFE4-F248-11E8-B48F-1D18A9856A87
  last_name: Fulek
  orcid: 0000-0001-8485-1774
- first_name: Bernd
  full_name: Gärtner, Bernd
  last_name: Gärtner
- first_name: Andrey
  full_name: Kupavskii, Andrey
  last_name: Kupavskii
- first_name: Pavel
  full_name: Valtr, Pavel
  last_name: Valtr
- first_name: Uli
  full_name: Wagner, Uli
  id: 36690CA2-F248-11E8-B48F-1D18A9856A87
  last_name: Wagner
  orcid: 0000-0002-1494-0568
citation:
  ama: 'Fulek R, Gärtner B, Kupavskii A, Valtr P, Wagner U. The crossing Tverberg
    theorem. In: <i>35th International Symposium on Computational Geometry</i>. Vol
    129. Schloss Dagstuhl - Leibniz-Zentrum für Informatik; 2019:38:1-38:13. doi:<a
    href="https://doi.org/10.4230/LIPICS.SOCG.2019.38">10.4230/LIPICS.SOCG.2019.38</a>'
  apa: 'Fulek, R., Gärtner, B., Kupavskii, A., Valtr, P., &#38; Wagner, U. (2019).
    The crossing Tverberg theorem. In <i>35th International Symposium on Computational
    Geometry</i> (Vol. 129, p. 38:1-38:13). Portland, OR, United States: Schloss Dagstuhl
    - Leibniz-Zentrum für Informatik. <a href="https://doi.org/10.4230/LIPICS.SOCG.2019.38">https://doi.org/10.4230/LIPICS.SOCG.2019.38</a>'
  chicago: Fulek, Radoslav, Bernd Gärtner, Andrey Kupavskii, Pavel Valtr, and Uli
    Wagner. “The Crossing Tverberg Theorem.” In <i>35th International Symposium on
    Computational Geometry</i>, 129:38:1-38:13. Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik, 2019. <a href="https://doi.org/10.4230/LIPICS.SOCG.2019.38">https://doi.org/10.4230/LIPICS.SOCG.2019.38</a>.
  ieee: R. Fulek, B. Gärtner, A. Kupavskii, P. Valtr, and U. Wagner, “The crossing
    Tverberg theorem,” in <i>35th International Symposium on Computational Geometry</i>,
    Portland, OR, United States, 2019, vol. 129, p. 38:1-38:13.
  ista: 'Fulek R, Gärtner B, Kupavskii A, Valtr P, Wagner U. 2019. The crossing Tverberg
    theorem. 35th International Symposium on Computational Geometry. SoCG 2019: Symposium
    on Computational Geometry, LIPIcs, vol. 129, 38:1-38:13.'
  mla: Fulek, Radoslav, et al. “The Crossing Tverberg Theorem.” <i>35th International
    Symposium on Computational Geometry</i>, vol. 129, Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik, 2019, p. 38:1-38:13, doi:<a href="https://doi.org/10.4230/LIPICS.SOCG.2019.38">10.4230/LIPICS.SOCG.2019.38</a>.
  short: R. Fulek, B. Gärtner, A. Kupavskii, P. Valtr, U. Wagner, in:, 35th International
    Symposium on Computational Geometry, Schloss Dagstuhl - Leibniz-Zentrum für Informatik,
    2019, p. 38:1-38:13.
conference:
  end_date: 2019-06-21
  location: Portland, OR, United States
  name: 'SoCG 2019: Symposium on Computational Geometry'
  start_date: 2019-06-18
date_created: 2019-07-17T10:35:04Z
date_published: 2019-06-01T00:00:00Z
date_updated: 2023-12-13T12:03:35Z
day: '01'
ddc:
- '000'
- '510'
department:
- _id: UlWa
doi: 10.4230/LIPICS.SOCG.2019.38
external_id:
  arxiv:
  - '1812.04911'
file:
- access_level: open_access
  checksum: d6d017f8b41291b94d102294fa96ae9c
  content_type: application/pdf
  creator: dernst
  date_created: 2019-07-24T06:54:52Z
  date_updated: 2020-07-14T12:47:35Z
  file_id: '6667'
  file_name: 2019_LIPICS_Fulek.pdf
  file_size: 559837
  relation: main_file
file_date_updated: 2020-07-14T12:47:35Z
has_accepted_license: '1'
intvolume: '       129'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '06'
oa: 1
oa_version: Published Version
page: 38:1-38:13
project:
- _id: 261FA626-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: M02281
  name: Eliminating intersections in drawings of graphs
publication: 35th International Symposium on Computational Geometry
publication_identifier:
  isbn:
  - '9783959771047'
  issn:
  - 1868-8969
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
quality_controlled: '1'
related_material:
  record:
  - id: '13974'
    relation: later_version
    status: public
scopus_import: 1
status: public
title: The crossing Tverberg theorem
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: 129
year: '2019'
...
---
_id: '6982'
abstract:
- lang: eng
  text: "We present an efficient algorithm for a problem in the interface between
    clustering and graph embeddings. An embedding ϕ : G → M of a graph G into a 2-manifold
    M maps the vertices in V(G) to distinct points and the edges in E(G) to interior-disjoint
    Jordan arcs between the corresponding vertices. In applications in clustering,
    cartography, and visualization, nearby vertices and edges are often bundled to
    the same point or overlapping arcs due to data compression or low resolution.
    This raises the computational problem of deciding whether a given map ϕ : G →
    M comes from an embedding. A map ϕ : G → M is a weak embedding if it can be perturbed
    into an embedding ψ ϵ : G → M with ‖ ϕ − ψ ϵ ‖ < ϵ for every ϵ > 0, where ‖.‖
    is the unform norm.\r\nA polynomial-time algorithm for recognizing weak embeddings
    has recently been found by Fulek and Kynčl. It reduces the problem to solving
    a system of linear equations over Z2. It runs in O(n2ω)≤ O(n4.75) time, where
    ω ∈ [2,2.373) is the matrix multiplication exponent and n is the number of vertices
    and edges of G. We improve the running time to O(n log n). Our algorithm is also
    conceptually simpler: We perform a sequence of local operations that gradually
    “untangles” the image ϕ(G) into an embedding ψ(G) or reports that ϕ is not a weak
    embedding. It combines local constraints on the orientation of subgraphs directly,
    thereby eliminating the need for solving large systems of linear equations.\r\n"
article_number: '50'
article_type: original
arxiv: 1
author:
- first_name: Hugo
  full_name: Akitaya, Hugo
  last_name: Akitaya
- first_name: Radoslav
  full_name: Fulek, Radoslav
  id: 39F3FFE4-F248-11E8-B48F-1D18A9856A87
  last_name: Fulek
  orcid: 0000-0001-8485-1774
- first_name: Csaba
  full_name: Tóth, Csaba
  last_name: Tóth
citation:
  ama: Akitaya H, Fulek R, Tóth C. Recognizing weak embeddings of graphs. <i>ACM Transactions
    on Algorithms</i>. 2019;15(4). doi:<a href="https://doi.org/10.1145/3344549">10.1145/3344549</a>
  apa: Akitaya, H., Fulek, R., &#38; Tóth, C. (2019). Recognizing weak embeddings
    of graphs. <i>ACM Transactions on Algorithms</i>. ACM. <a href="https://doi.org/10.1145/3344549">https://doi.org/10.1145/3344549</a>
  chicago: Akitaya, Hugo, Radoslav Fulek, and Csaba Tóth. “Recognizing Weak Embeddings
    of Graphs.” <i>ACM Transactions on Algorithms</i>. ACM, 2019. <a href="https://doi.org/10.1145/3344549">https://doi.org/10.1145/3344549</a>.
  ieee: H. Akitaya, R. Fulek, and C. Tóth, “Recognizing weak embeddings of graphs,”
    <i>ACM Transactions on Algorithms</i>, vol. 15, no. 4. ACM, 2019.
  ista: Akitaya H, Fulek R, Tóth C. 2019. Recognizing weak embeddings of graphs. ACM
    Transactions on Algorithms. 15(4), 50.
  mla: Akitaya, Hugo, et al. “Recognizing Weak Embeddings of Graphs.” <i>ACM Transactions
    on Algorithms</i>, vol. 15, no. 4, 50, ACM, 2019, doi:<a href="https://doi.org/10.1145/3344549">10.1145/3344549</a>.
  short: H. Akitaya, R. Fulek, C. Tóth, ACM Transactions on Algorithms 15 (2019).
date_created: 2019-11-04T15:45:17Z
date_published: 2019-10-01T00:00:00Z
date_updated: 2023-09-15T12:19:31Z
day: '01'
department:
- _id: UlWa
doi: 10.1145/3344549
external_id:
  arxiv:
  - '1709.09209'
intvolume: '        15'
issue: '4'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1709.09209
month: '10'
oa: 1
oa_version: Preprint
project:
- _id: 261FA626-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: M02281
  name: Eliminating intersections in drawings of graphs
publication: ACM Transactions on Algorithms
publication_status: published
publisher: ACM
quality_controlled: '1'
related_material:
  record:
  - id: '309'
    relation: earlier_version
    status: public
scopus_import: 1
status: public
title: Recognizing weak embeddings of graphs
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 15
year: '2019'
...
---
_id: '7034'
abstract:
- lang: eng
  text: We find a graph of genus 5 and its drawing on the orientable surface of genus
    4 with every pair of independent edges crossing an even number of times. This
    shows that the strong Hanani–Tutte theorem cannot be extended to the orientable
    surface of genus 4. As a base step in the construction we use a counterexample
    to an extension of the unified Hanani–Tutte theorem on the torus.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Radoslav
  full_name: Fulek, Radoslav
  id: 39F3FFE4-F248-11E8-B48F-1D18A9856A87
  last_name: Fulek
  orcid: 0000-0001-8485-1774
- first_name: Jan
  full_name: Kynčl, Jan
  last_name: Kynčl
citation:
  ama: Fulek R, Kynčl J. Counterexample to an extension of the Hanani-Tutte theorem
    on the surface of genus 4. <i>Combinatorica</i>. 2019;39(6):1267-1279. doi:<a
    href="https://doi.org/10.1007/s00493-019-3905-7">10.1007/s00493-019-3905-7</a>
  apa: Fulek, R., &#38; Kynčl, J. (2019). Counterexample to an extension of the Hanani-Tutte
    theorem on the surface of genus 4. <i>Combinatorica</i>. Springer Nature. <a href="https://doi.org/10.1007/s00493-019-3905-7">https://doi.org/10.1007/s00493-019-3905-7</a>
  chicago: Fulek, Radoslav, and Jan Kynčl. “Counterexample to an Extension of the
    Hanani-Tutte Theorem on the Surface of Genus 4.” <i>Combinatorica</i>. Springer
    Nature, 2019. <a href="https://doi.org/10.1007/s00493-019-3905-7">https://doi.org/10.1007/s00493-019-3905-7</a>.
  ieee: R. Fulek and J. Kynčl, “Counterexample to an extension of the Hanani-Tutte
    theorem on the surface of genus 4,” <i>Combinatorica</i>, vol. 39, no. 6. Springer
    Nature, pp. 1267–1279, 2019.
  ista: Fulek R, Kynčl J. 2019. Counterexample to an extension of the Hanani-Tutte
    theorem on the surface of genus 4. Combinatorica. 39(6), 1267–1279.
  mla: Fulek, Radoslav, and Jan Kynčl. “Counterexample to an Extension of the Hanani-Tutte
    Theorem on the Surface of Genus 4.” <i>Combinatorica</i>, vol. 39, no. 6, Springer
    Nature, 2019, pp. 1267–79, doi:<a href="https://doi.org/10.1007/s00493-019-3905-7">10.1007/s00493-019-3905-7</a>.
  short: R. Fulek, J. Kynčl, Combinatorica 39 (2019) 1267–1279.
date_created: 2019-11-18T14:29:50Z
date_published: 2019-10-29T00:00:00Z
date_updated: 2023-08-30T07:26:25Z
day: '29'
department:
- _id: UlWa
doi: 10.1007/s00493-019-3905-7
ec_funded: 1
external_id:
  arxiv:
  - '1709.00508'
  isi:
  - '000493267200003'
intvolume: '        39'
isi: 1
issue: '6'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1709.00508
month: '10'
oa: 1
oa_version: Preprint
page: 1267-1279
project:
- _id: 25681D80-B435-11E9-9278-68D0E5697425
  call_identifier: FP7
  grant_number: '291734'
  name: International IST Postdoc Fellowship Programme
- _id: 261FA626-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: M02281
  name: Eliminating intersections in drawings of graphs
publication: Combinatorica
publication_identifier:
  eissn:
  - 1439-6912
  issn:
  - 0209-9683
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Counterexample to an extension of the Hanani-Tutte theorem on the surface of
  genus 4
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 39
year: '2019'
...
---
_id: '7401'
abstract:
- lang: eng
  text: 'The genus g(G) of a graph G is the minimum g such that G has an embedding
    on the orientable surface M_g of genus g. A drawing of a graph on a surface is
    independently even if every pair of nonadjacent edges in the drawing crosses an
    even number of times. The Z_2-genus of a graph G, denoted by g_0(G), is the minimum
    g such that G has an independently even drawing on M_g. By a result of Battle,
    Harary, Kodama and Youngs from 1962, the graph genus is additive over 2-connected
    blocks. In 2013, Schaefer and Stefankovic proved that the Z_2-genus of a graph
    is additive over 2-connected blocks as well, and asked whether this result can
    be extended to so-called 2-amalgamations, as an analogue of results by Decker,
    Glover, Huneke, and Stahl for the genus. We give the following partial answer.
    If G=G_1 cup G_2, G_1 and G_2 intersect in two vertices u and v, and G-u-v has
    k connected components (among which we count the edge uv if present), then |g_0(G)-(g_0(G_1)+g_0(G_2))|<=k+1.
    For complete bipartite graphs K_{m,n}, with n >= m >= 3, we prove that g_0(K_{m,n})/g(K_{m,n})=1-O(1/n).
    Similar results are proved also for the Euler Z_2-genus. We express the Z_2-genus
    of a graph using the minimum rank of partial symmetric matrices over Z_2; a problem
    that might be of independent interest. '
alternative_title:
- LIPIcs
article_number: '39'
article_processing_charge: No
arxiv: 1
author:
- first_name: Radoslav
  full_name: Fulek, Radoslav
  id: 39F3FFE4-F248-11E8-B48F-1D18A9856A87
  last_name: Fulek
  orcid: 0000-0001-8485-1774
- first_name: Jan
  full_name: Kyncl, Jan
  last_name: Kyncl
citation:
  ama: 'Fulek R, Kyncl J. Z_2-Genus of graphs and minimum rank of partial symmetric
    matrices. In: <i>35th International Symposium on Computational Geometry (SoCG
    2019)</i>. Vol 129. Schloss Dagstuhl - Leibniz-Zentrum für Informatik; 2019. doi:<a
    href="https://doi.org/10.4230/LIPICS.SOCG.2019.39">10.4230/LIPICS.SOCG.2019.39</a>'
  apa: 'Fulek, R., &#38; Kyncl, J. (2019). Z_2-Genus of graphs and minimum rank of
    partial symmetric matrices. In <i>35th International Symposium on Computational
    Geometry (SoCG 2019)</i> (Vol. 129). Portland, OR, United States: Schloss Dagstuhl
    - Leibniz-Zentrum für Informatik. <a href="https://doi.org/10.4230/LIPICS.SOCG.2019.39">https://doi.org/10.4230/LIPICS.SOCG.2019.39</a>'
  chicago: Fulek, Radoslav, and Jan Kyncl. “Z_2-Genus of Graphs and Minimum Rank of
    Partial Symmetric Matrices.” In <i>35th International Symposium on Computational
    Geometry (SoCG 2019)</i>, Vol. 129. Schloss Dagstuhl - Leibniz-Zentrum für Informatik,
    2019. <a href="https://doi.org/10.4230/LIPICS.SOCG.2019.39">https://doi.org/10.4230/LIPICS.SOCG.2019.39</a>.
  ieee: R. Fulek and J. Kyncl, “Z_2-Genus of graphs and minimum rank of partial symmetric
    matrices,” in <i>35th International Symposium on Computational Geometry (SoCG
    2019)</i>, Portland, OR, United States, 2019, vol. 129.
  ista: 'Fulek R, Kyncl J. 2019. Z_2-Genus of graphs and minimum rank of partial symmetric
    matrices. 35th International Symposium on Computational Geometry (SoCG 2019).
    SoCG: Symposium on Computational Geometry, LIPIcs, vol. 129, 39.'
  mla: Fulek, Radoslav, and Jan Kyncl. “Z_2-Genus of Graphs and Minimum Rank of Partial
    Symmetric Matrices.” <i>35th International Symposium on Computational Geometry
    (SoCG 2019)</i>, vol. 129, 39, Schloss Dagstuhl - Leibniz-Zentrum für Informatik,
    2019, doi:<a href="https://doi.org/10.4230/LIPICS.SOCG.2019.39">10.4230/LIPICS.SOCG.2019.39</a>.
  short: R. Fulek, J. Kyncl, in:, 35th International Symposium on Computational Geometry
    (SoCG 2019), Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2019.
conference:
  end_date: 2019-06-21
  location: Portland, OR, United States
  name: 'SoCG: Symposium on Computational Geometry'
  start_date: 2019-06-18
date_created: 2020-01-29T16:17:05Z
date_published: 2019-06-01T00:00:00Z
date_updated: 2021-01-12T08:13:24Z
day: '01'
ddc:
- '000'
department:
- _id: UlWa
doi: 10.4230/LIPICS.SOCG.2019.39
external_id:
  arxiv:
  - '1903.08637'
file:
- access_level: open_access
  checksum: aac37b09118cc0ab58cf77129e691f8c
  content_type: application/pdf
  creator: dernst
  date_created: 2020-02-04T09:14:31Z
  date_updated: 2020-07-14T12:47:57Z
  file_id: '7445'
  file_name: 2019_LIPIcs_Fulek.pdf
  file_size: 628347
  relation: main_file
file_date_updated: 2020-07-14T12:47:57Z
has_accepted_license: '1'
intvolume: '       129'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
project:
- _id: 261FA626-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: M02281
  name: Eliminating intersections in drawings of graphs
publication: 35th International Symposium on Computational Geometry (SoCG 2019)
publication_identifier:
  isbn:
  - 978-3-95977-104-7
  issn:
  - 1868-8969
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
quality_controlled: '1'
scopus_import: 1
status: public
title: Z_2-Genus of graphs and minimum rank of partial symmetric matrices
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: 129
year: '2019'
...
---
_id: '185'
abstract:
- lang: eng
  text: We resolve in the affirmative conjectures of A. Skopenkov and Repovš (1998),
    and M. Skopenkov (2003) generalizing the classical Hanani-Tutte theorem to the
    setting of approximating maps of graphs on 2-dimensional surfaces by embeddings.
    Our proof of this result is constructive and almost immediately implies an efficient
    algorithm for testing whether a given piecewise linear map of a graph in a surface
    is approximable by an embedding. More precisely, an instance of this problem consists
    of (i) a graph G whose vertices are partitioned into clusters and whose inter-cluster
    edges are partitioned into bundles, and (ii) a region R of a 2-dimensional compact
    surface M given as the union of a set of pairwise disjoint discs corresponding
    to the clusters and a set of pairwise disjoint &quot;pipes&quot; corresponding
    to the bundles, connecting certain pairs of these discs. We are to decide whether
    G can be embedded inside M so that the vertices in every cluster are drawn in
    the corresponding disc, the edges in every bundle pass only through its corresponding
    pipe, and every edge crosses the boundary of each disc at most once.
alternative_title:
- Leibniz International Proceedings in Information, LIPIcs
article_number: '39'
author:
- first_name: Radoslav
  full_name: Fulek, Radoslav
  id: 39F3FFE4-F248-11E8-B48F-1D18A9856A87
  last_name: Fulek
  orcid: 0000-0001-8485-1774
- first_name: Jan
  full_name: Kynčl, Jan
  last_name: Kynčl
citation:
  ama: 'Fulek R, Kynčl J. Hanani-Tutte for approximating maps of graphs. In: Vol 99.
    Schloss Dagstuhl - Leibniz-Zentrum für Informatik; 2018. doi:<a href="https://doi.org/10.4230/LIPIcs.SoCG.2018.39">10.4230/LIPIcs.SoCG.2018.39</a>'
  apa: 'Fulek, R., &#38; Kynčl, J. (2018). Hanani-Tutte for approximating maps of
    graphs (Vol. 99). Presented at the SoCG: Symposium on Computational Geometry,
    Budapest, Hungary: Schloss Dagstuhl - Leibniz-Zentrum für Informatik. <a href="https://doi.org/10.4230/LIPIcs.SoCG.2018.39">https://doi.org/10.4230/LIPIcs.SoCG.2018.39</a>'
  chicago: Fulek, Radoslav, and Jan Kynčl. “Hanani-Tutte for Approximating Maps of
    Graphs,” Vol. 99. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2018. <a
    href="https://doi.org/10.4230/LIPIcs.SoCG.2018.39">https://doi.org/10.4230/LIPIcs.SoCG.2018.39</a>.
  ieee: 'R. Fulek and J. Kynčl, “Hanani-Tutte for approximating maps of graphs,” presented
    at the SoCG: Symposium on Computational Geometry, Budapest, Hungary, 2018, vol.
    99.'
  ista: 'Fulek R, Kynčl J. 2018. Hanani-Tutte for approximating maps of graphs. SoCG:
    Symposium on Computational Geometry, Leibniz International Proceedings in Information,
    LIPIcs, vol. 99, 39.'
  mla: Fulek, Radoslav, and Jan Kynčl. <i>Hanani-Tutte for Approximating Maps of Graphs</i>.
    Vol. 99, 39, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2018, doi:<a href="https://doi.org/10.4230/LIPIcs.SoCG.2018.39">10.4230/LIPIcs.SoCG.2018.39</a>.
  short: R. Fulek, J. Kynčl, in:, Schloss Dagstuhl - Leibniz-Zentrum für Informatik,
    2018.
conference:
  end_date: 2018-06-14
  location: Budapest, Hungary
  name: 'SoCG: Symposium on Computational Geometry'
  start_date: 2018-06-11
date_created: 2018-12-11T11:45:04Z
date_published: 2018-01-01T00:00:00Z
date_updated: 2021-01-12T06:53:36Z
day: '01'
ddc:
- '510'
department:
- _id: UlWa
doi: 10.4230/LIPIcs.SoCG.2018.39
file:
- access_level: open_access
  checksum: f1b94f1a75b37c414a1f61d59fb2cd4c
  content_type: application/pdf
  creator: dernst
  date_created: 2018-12-17T12:33:52Z
  date_updated: 2020-07-14T12:45:19Z
  file_id: '5701'
  file_name: 2018_LIPIcs_Fulek.pdf
  file_size: 718857
  relation: main_file
file_date_updated: 2020-07-14T12:45:19Z
has_accepted_license: '1'
intvolume: '        99'
language:
- iso: eng
month: '01'
oa: 1
oa_version: Published Version
project:
- _id: 261FA626-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: M02281
  name: Eliminating intersections in drawings of graphs
publication_identifier:
  isbn:
  - 978-3-95977-066-8
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
publist_id: '7735'
quality_controlled: '1'
scopus_import: 1
status: public
title: Hanani-Tutte for approximating maps of 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: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 99
year: '2018'
...
---
_id: '186'
abstract:
- lang: eng
  text: 'A drawing of a graph on a surface is independently even if every pair of
    nonadjacent edges in the drawing crosses an even number of times. The ℤ2-genus
    of a graph G is the minimum g such that G has an independently even drawing on
    the orientable surface of genus g. An unpublished result by Robertson and Seymour
    implies that for every t, every graph of sufficiently large genus contains as
    a minor a projective t × t grid or one of the following so-called t-Kuratowski
    graphs: K3, t, or t copies of K5 or K3,3 sharing at most 2 common vertices. We
    show that the ℤ2-genus of graphs in these families is unbounded in t; in fact,
    equal to their genus. Together, this implies that the genus of a graph is bounded
    from above by a function of its ℤ2-genus, solving a problem posed by Schaefer
    and Štefankovič, and giving an approximate version of the Hanani-Tutte theorem
    on orientable surfaces.'
alternative_title:
- LIPIcs
article_processing_charge: No
arxiv: 1
author:
- first_name: Radoslav
  full_name: Fulek, Radoslav
  id: 39F3FFE4-F248-11E8-B48F-1D18A9856A87
  last_name: Fulek
  orcid: 0000-0001-8485-1774
- first_name: Jan
  full_name: Kynčl, Jan
  last_name: Kynčl
citation:
  ama: 'Fulek R, Kynčl J. The ℤ2-Genus of Kuratowski minors. In: Vol 99. Schloss Dagstuhl
    - Leibniz-Zentrum für Informatik; 2018:40.1-40.14. doi:<a href="https://doi.org/10.4230/LIPIcs.SoCG.2018.40">10.4230/LIPIcs.SoCG.2018.40</a>'
  apa: 'Fulek, R., &#38; Kynčl, J. (2018). The ℤ2-Genus of Kuratowski minors (Vol.
    99, p. 40.1-40.14). Presented at the SoCG: Symposium on Computational Geometry,
    Budapest, Hungary: Schloss Dagstuhl - Leibniz-Zentrum für Informatik. <a href="https://doi.org/10.4230/LIPIcs.SoCG.2018.40">https://doi.org/10.4230/LIPIcs.SoCG.2018.40</a>'
  chicago: Fulek, Radoslav, and Jan Kynčl. “The ℤ2-Genus of Kuratowski Minors,” 99:40.1-40.14.
    Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2018. <a href="https://doi.org/10.4230/LIPIcs.SoCG.2018.40">https://doi.org/10.4230/LIPIcs.SoCG.2018.40</a>.
  ieee: 'R. Fulek and J. Kynčl, “The ℤ2-Genus of Kuratowski minors,” presented at
    the SoCG: Symposium on Computational Geometry, Budapest, Hungary, 2018, vol. 99,
    p. 40.1-40.14.'
  ista: 'Fulek R, Kynčl J. 2018. The ℤ2-Genus of Kuratowski minors. SoCG: Symposium
    on Computational Geometry, LIPIcs, vol. 99, 40.1-40.14.'
  mla: Fulek, Radoslav, and Jan Kynčl. <i>The ℤ2-Genus of Kuratowski Minors</i>. Vol.
    99, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2018, p. 40.1-40.14, doi:<a
    href="https://doi.org/10.4230/LIPIcs.SoCG.2018.40">10.4230/LIPIcs.SoCG.2018.40</a>.
  short: R. Fulek, J. Kynčl, in:, Schloss Dagstuhl - Leibniz-Zentrum für Informatik,
    2018, p. 40.1-40.14.
conference:
  end_date: 2018-06-14
  location: Budapest, Hungary
  name: 'SoCG: Symposium on Computational Geometry'
  start_date: 2018-06-11
date_created: 2018-12-11T11:45:05Z
date_published: 2018-06-11T00:00:00Z
date_updated: 2023-08-14T12:43:51Z
day: '11'
department:
- _id: UlWa
doi: 10.4230/LIPIcs.SoCG.2018.40
external_id:
  arxiv:
  - '1803.05085'
intvolume: '        99'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1803.05085
month: '06'
oa: 1
oa_version: Submitted Version
page: 40.1 - 40.14
project:
- _id: 261FA626-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: M02281
  name: Eliminating intersections in drawings of graphs
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
publist_id: '7734'
quality_controlled: '1'
related_material:
  record:
  - id: '11593'
    relation: later_version
    status: public
scopus_import: '1'
status: public
title: The ℤ2-Genus of Kuratowski minors
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 99
year: '2018'
...
---
_id: '309'
abstract:
- lang: eng
  text: 'We present an efficient algorithm for a problem in the interface between
    clustering and graph embeddings. An embedding '' : G ! M of a graph G into a 2manifold
    M maps the vertices in V (G) to distinct points and the edges in E(G) to interior-disjoint
    Jordan arcs between the corresponding vertices. In applications in clustering,
    cartography, and visualization, nearby vertices and edges are often bundled to
    a common node or arc, due to data compression or low resolution. This raises the
    computational problem of deciding whether a given map '' : G ! M comes from an
    embedding. A map '' : G ! M is a weak embedding if it can be perturbed into an
    embedding ψ: G ! M with k'' "k < " for every &quot; &gt; 0. A polynomial-time
    algorithm for recognizing weak embeddings was recently found by Fulek and Kyncl
    [14], which reduces to solving a system of linear equations over Z2. It runs in
    O(n2!) O(n4:75) time, where 2:373 is the matrix multiplication exponent and n
    is the number of vertices and edges of G. We improve the running time to O(n log
    n). Our algorithm is also conceptually simpler than [14]: We perform a sequence
    of local operations that gradually &quot;untangles&quot; the image ''(G) into
    an embedding (G), or reports that '' is not a weak embedding. It generalizes a
    recent technique developed for the case that G is a cycle and the embedding is
    a simple polygon [1], and combines local constraints on the orientation of subgraphs
    directly, thereby eliminating the need for solving large systems of linear equations.'
acknowledgement: '∗Research supported in part by the NSF awards CCF-1422311 and CCF-1423615,
  and the Science Without Borders program. The second author gratefully acknowledges
  support from Austrian Science Fund (FWF): M2281-N35.'
article_processing_charge: No
arxiv: 1
author:
- first_name: Hugo
  full_name: Akitaya, Hugo
  last_name: Akitaya
- first_name: Radoslav
  full_name: Fulek, Radoslav
  id: 39F3FFE4-F248-11E8-B48F-1D18A9856A87
  last_name: Fulek
  orcid: 0000-0001-8485-1774
- first_name: Csaba
  full_name: Tóth, Csaba
  last_name: Tóth
citation:
  ama: 'Akitaya H, Fulek R, Tóth C. Recognizing weak embeddings of graphs. In: ACM;
    2018:274-292. doi:<a href="https://doi.org/10.1137/1.9781611975031.20">10.1137/1.9781611975031.20</a>'
  apa: 'Akitaya, H., Fulek, R., &#38; Tóth, C. (2018). Recognizing weak embeddings
    of graphs (pp. 274–292). Presented at the SODA: Symposium on Discrete Algorithms,
    New Orleans, LA, USA: ACM. <a href="https://doi.org/10.1137/1.9781611975031.20">https://doi.org/10.1137/1.9781611975031.20</a>'
  chicago: Akitaya, Hugo, Radoslav Fulek, and Csaba Tóth. “Recognizing Weak Embeddings
    of Graphs,” 274–92. ACM, 2018. <a href="https://doi.org/10.1137/1.9781611975031.20">https://doi.org/10.1137/1.9781611975031.20</a>.
  ieee: 'H. Akitaya, R. Fulek, and C. Tóth, “Recognizing weak embeddings of graphs,”
    presented at the SODA: Symposium on Discrete Algorithms, New Orleans, LA, USA,
    2018, pp. 274–292.'
  ista: 'Akitaya H, Fulek R, Tóth C. 2018. Recognizing weak embeddings of graphs.
    SODA: Symposium on Discrete Algorithms, 274–292.'
  mla: Akitaya, Hugo, et al. <i>Recognizing Weak Embeddings of Graphs</i>. ACM, 2018,
    pp. 274–92, doi:<a href="https://doi.org/10.1137/1.9781611975031.20">10.1137/1.9781611975031.20</a>.
  short: H. Akitaya, R. Fulek, C. Tóth, in:, ACM, 2018, pp. 274–292.
conference:
  end_date: 2018-01-10
  location: New Orleans, LA, USA
  name: 'SODA: Symposium on Discrete Algorithms'
  start_date: 2018-01-07
date_created: 2018-12-11T11:45:45Z
date_published: 2018-01-01T00:00:00Z
date_updated: 2023-09-15T12:19:32Z
day: '01'
department:
- _id: UlWa
doi: 10.1137/1.9781611975031.20
external_id:
  arxiv:
  - '1709.09209'
  isi:
  - '000483921200021'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1709.09209
month: '01'
oa: 1
oa_version: Preprint
page: 274 - 292
project:
- _id: 261FA626-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: M02281
  name: Eliminating intersections in drawings of graphs
publication_status: published
publisher: ACM
publist_id: '7556'
quality_controlled: '1'
related_material:
  record:
  - id: '6982'
    relation: later_version
    status: public
scopus_import: '1'
status: public
title: Recognizing weak embeddings of graphs
type: conference
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2018'
...
---
_id: '6517'
abstract:
- lang: eng
  text: A (possibly degenerate) drawing of a graph G in the plane is approximable
    by an embedding if it can be turned into an embedding by an arbitrarily small
    perturbation. We show that testing, whether a drawing of a planar graph G in the
    plane is approximable by an embedding, can be carried out in polynomial time,
    if a desired embedding of G belongs to a fixed isotopy class, i.e., the rotation
    system (or equivalently the faces) of the embedding of G and the choice of outer
    face are fixed. In other words, we show that c-planarity with embedded pipes is
    tractable for graphs with fixed embeddings. To the best of our knowledge an analogous
    result was previously known essentially only when G is a cycle.
article_number: '34'
author:
- first_name: Radoslav
  full_name: Fulek, Radoslav
  id: 39F3FFE4-F248-11E8-B48F-1D18A9856A87
  last_name: Fulek
  orcid: 0000-0001-8485-1774
citation:
  ama: 'Fulek R. Embedding graphs into embedded graphs. In: Vol 92. Schloss Dagstuhl
    - Leibniz-Zentrum für Informatik; 2017. doi:<a href="https://doi.org/10.4230/LIPICS.ISAAC.2017.34">10.4230/LIPICS.ISAAC.2017.34</a>'
  apa: 'Fulek, R. (2017). Embedding graphs into embedded graphs (Vol. 92). Presented
    at the ISAAC: International Symposium on Algorithms and Computation, Phuket, Thailand:
    Schloss Dagstuhl - Leibniz-Zentrum für Informatik. <a href="https://doi.org/10.4230/LIPICS.ISAAC.2017.34">https://doi.org/10.4230/LIPICS.ISAAC.2017.34</a>'
  chicago: Fulek, Radoslav. “Embedding Graphs into Embedded Graphs,” Vol. 92. Schloss
    Dagstuhl - Leibniz-Zentrum für Informatik, 2017. <a href="https://doi.org/10.4230/LIPICS.ISAAC.2017.34">https://doi.org/10.4230/LIPICS.ISAAC.2017.34</a>.
  ieee: 'R. Fulek, “Embedding graphs into embedded graphs,” presented at the ISAAC:
    International Symposium on Algorithms and Computation, Phuket, Thailand, 2017,
    vol. 92.'
  ista: 'Fulek R. 2017. Embedding graphs into embedded graphs. ISAAC: International
    Symposium on Algorithms and Computation vol. 92, 34.'
  mla: Fulek, Radoslav. <i>Embedding Graphs into Embedded Graphs</i>. Vol. 92, 34,
    Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2017, doi:<a href="https://doi.org/10.4230/LIPICS.ISAAC.2017.34">10.4230/LIPICS.ISAAC.2017.34</a>.
  short: R. Fulek, in:, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2017.
conference:
  end_date: 2017-12-22
  location: Phuket, Thailand
  name: 'ISAAC: International Symposium on Algorithms and Computation'
  start_date: 2017-12-09
date_created: 2019-06-04T12:11:52Z
date_published: 2017-12-01T00:00:00Z
date_updated: 2021-01-12T08:07:51Z
day: '01'
ddc:
- '510'
department:
- _id: UlWa
doi: 10.4230/LIPICS.ISAAC.2017.34
ec_funded: 1
file:
- access_level: open_access
  checksum: fc7a643e29621c8bbe49d36b39081f31
  content_type: application/pdf
  creator: kschuh
  date_created: 2019-06-04T12:20:35Z
  date_updated: 2020-07-14T12:47:33Z
  file_id: '6518'
  file_name: 2017_LIPIcs-Fulek.pdf
  file_size: 588982
  relation: main_file
file_date_updated: 2020-07-14T12:47:33Z
has_accepted_license: '1'
intvolume: '        92'
language:
- iso: eng
month: '12'
oa: 1
oa_version: Published Version
project:
- _id: 25681D80-B435-11E9-9278-68D0E5697425
  call_identifier: FP7
  grant_number: '291734'
  name: International IST Postdoc Fellowship Programme
- _id: 261FA626-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: M02281
  name: Eliminating intersections in drawings of graphs
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
quality_controlled: '1'
scopus_import: 1
status: public
title: Embedding graphs into embedded 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: 92
year: '2017'
...
