Florian Lehner's Webpage

Personal Profile

About me

I recently finished my Ph.D. in the framework of the DK Discrete Mathematics under the supervision of J. Wallner.

Currently I am working as a research assistant in the discrete mathematics group at the University of Hamburg.

Research

My research interest include, but are not limited to
infinite, locally finite graphs
connections between groups and graphs
games on graphs
random structures and probabilistic methods

That's me!

Resume

Employment

Research Assistant
University of Hamburg
Department of Mathematics.
2015 – Pres.
University Assistant
Graz University of Technology
Institute of Geometry.
2011 – 2015
Teaching Assistant
Graz University of Technology
Institute of Mathematics A, B and C and Institute for Software Technology.
2007 – 2010

Education

PhD: Mathematics and Scientific Computing
Graz University of Technology
PhD thesis: Symmetry breaking in graphs and groups.
Associated member of the DK Discrete Mathematics. Graduation with highest distinctions "sub auspiciis Praesidentis"
2011 – 2014
Master Programme: Mathematical Computer Science
Graz University of Technology
2008 – 2011
Bachelor Programme: Technical Mathematics
Graz University of Technology
2005 – 2008
Diploma Programme: Electrical Engineering
Graz University of Technology
Changed my major to mathematics after one year.
2004 – 2005

Publications

Articles

You can also download a BibTeX-file of this list.

[14] A counterexample to the reconstruction conjecture for locally finite trees. (with N. Bowler, J. Erde, P. Heinig, and M. Pitz)
2016, submitted.
[pdf]
[13] Breaking graph symmetries by edge colourings.
2016, submitted.
[pdf]
[12] Fast factorization of Cartesian products of (directed) hypergraphs. (with M. Hellmuth)
Theoretical Computer Science, 615, pp. 1 – 11, 2016.
[pdf]
[11] Maximising the number of independent sets in connected graphs. (with S. Wagner)
2015, submitted.
[pdf]
[10] Local finiteness, distinguishing numbers and Tucker's conjecture. (with R. G. Möller)
Electronic Journal of Combinatorics, 22 (4), 2015, research paper #19.
[pdf]
[9] Pursuit evasion on infinite graphs.
Theoretical Computer Science, 2016, to appear.
[pdf]
[8] The Cartesian product of graphs with loops. (with T. Boiko, J. Cuno, W. Imrich, and C. E. van de Woestijne)
Ars Mathematica Contemporanea, 11 (1), pp. 1 – 9, 2016.
[pdf]
[7] Clique trees of infinite locally finite chordal graphs. (with C. Temmel)
2013, submitted.
[pdf]
[6] Extending cycles locally to Hamilton cycles. (with M. Hamann and J. Pott)
Electronic Journal of Combinatorics, 23 (1), 2016, research paper #49.
[pdf]
[5] Random colorings and automorphism breaking in locally finite graphs.
Combinatorics, Probability and Computing, 22 (6), pp. 885 – 909, 2013.
[pdf]
[4] Distinguishing graphs with intermediate growth.
Combinatorica, 2013, to appear.
[pdf]
[3] Endomorphism breaking in graphs. (with W. Imrich, R. Kalinowski, and M. Pilśniak)
Electronic Journal of Combinatorics, 21 (1), 2014, research paper #16.
[pdf]
[2] Distinguishing graphs with infinite motion and nonlinear growth. (with J. Cuno and W. Imrich)
Ars Mathematica Contemporanea, 7, pp. 201 – 213, 2014.
[pdf]
[1] On spanning tree packings of highly edge connected graphs.
Journal of Combinatorial Theory, Series B, 105, pp. 93 – 126, 2014.
[pdf]

Theses

[2] Symmetry breaking in graphs and groups
Ph.D. Thesis, TU Graz, 2014.
[pdf]
[1] The line graph of every locally finite 6-edge-connected graph with finitely many ends is hamiltonian.
Master thesis, TU Graz, 2011.
[pdf]

Honours & Awards

Studienpreis der OeMG

2015

Awarded by the Austrian Mathematical Society for outstanding dissertations in mathematics, only one award in 2015.

Exzellenzstipendium

2015

Awarded by the Austrian ministry of science for outstanding study performance.

Promotio sub auspiciis praesidentis

2015

Highest level of distinction for study performance in Austria, awarded for passing all final exams starting from secondary education with distinction.

CMSA Student Prize

2013

Awarded for the best student presentation at 37ACCMCC.

Leistungsstipendium

2006/07 & 2008/09

Merit based scholarship for undergraduate students awarded by TU Graz.

Conference & Seminar Talks

2016

Breaking graph symmetries by edge colourings.
Algebra seminar. Lincoln University.
Oct 2016
The reconstruction problem for infinite graphs.
Leoben–Ljubljana Graph Theory Seminar. Judenburg.
Sep 2016
The reconstruction problem for infinite graphs.
CSASC 2016. Institut d’Estudis Catalans.
Sep 2016
Invited talk:
The reconstruction problem for infinite graphs.

Symposium on Discrete Mathematics. Freie Universität Berlin.
Jul 2016
Automorphism groups of one–ended graphs.
Festkolloquium anlässlich des 75. Geburtstages von Wilfried Imrich. TU Graz.
Jun 2016

2015

Cops, robbers, and infinite graphs.
39th ACCMCC. University of Queensland.
Dec 2015
Cops, robbers, and infinite graphs.
Mathematics Seminar. Univesity of Iceland.
Sep 2015
Cops, robbers, and infinite graphs.
Mathematikseminar. Universität Greifswald.
Jul 2015
Random colourings and automorphism breaking in locally finite graphs.
8th Slovenian Conference on Graph Theory. Kranjska Gora.
Jun 2015
Cops and robbers on infinite graphs.
Seminar za diskretno matematiko. University of Ljubljana.
Jan 2015

2014

Cops, robbers, and infinite graphs.
7th Cracow Conference on Graph Theory. Rytro.
Jun 2014
Invited talk:
Symmetry breaking in graphs and groups.

Ljubljana–Leoben Graph Theory Seminar. Koper.
Jun 2014
Breaking graph symmetries by random colourings.
Groups, Graphs, and Random Walks. Cortona.
Jun 2014
Chasing robbers on infinite graphs.
Mathematics Colloquium. Universiteit Stellenbosch.
Apr 2014
Cops and robbers on infinite graphs.
Seminar Diskrete Mathematik und Optimierung. TU Graz.
Mar 2014

2013

Almost all colourings are almost distinguishing.
37th ACCMCC. University of Western Australia.
Dec 2013
Symmetry braking in graphs.
Mathematics Colloquium. Vrije Universiteit Amsterdam.
Nov 2013
Random colourings and automorphism braking in graphs.
18th ÖMG-DMV-Congress. Universität Innsbruck.
Sep 2013
Random colourings and automorphism braking in graphs.
Leoben–Ljubljana Graph Theory Seminar. Bildungshaus Mariatrost, Graz.
Sep 2013
Symmetry breaking in graphs.
Mathematics Seminar. Univesity of Iceland.
Sep 2013
Stabilisers of random colourings in subdegree finite permutation groups.
24th British Combinatorial Conference. Royal Holloway.
Jun 2013
Automorphism breaking in locally finite graphs.
CanaDAM 2013. Memorial University, Newfoundland.
Jun 2013
Automorphism breaking in graphs.
Combinatorics Seminar. University of Warwick.
May 2013
Symmetries of random graph colourings.
Mathematics Seminar. University of Liverpool.
May 2013
Distinguishing graphs with intermediate growth.
Seminar IMFM in FNM v Mariboru iz diskretne matematike. University of Maribor.
Jan 2013

2012

Distinguishing graphs with intermediate growth.
36th ACCMCC. University of New South Wales.
Dec 2012
Spanning tree packings in highly edge connected graphs.
Mathematisches Forschungsseminar. Universität Hamburg.
Jun 2012

2011

A connectivity condition for hamiltonicity of locally finite line graphs.
Discrete Mathematics Day. TU Graz.
Jun 2011

Contact

Address

Florian Lehner
University of Hamburg, Department of Mathematics
Bundesstraße 55
20146 Hamburg

E-Mail

mail@florian-lehner.net