Tomaž Pisanski

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Tomaž Pisanski
Tomaz Pisanski age 70 (cropped).jpg
Born (1949-05-24) May 24, 1949 (age 71)
Nationality Slovene
Alma mater University of Ljubljana, Pennsylvania State University
Scientific career
Fields Topological graph theory, Algebraic graph theory, Discrete mathematics, Configuration (geometry).
Institutions University of Primorska
Doctoral advisor Torrence Parsons

Tomaž (Tomo) Pisanski (born May 24, 1949 in Ljubljana, Slovenia) is a Slovenian mathematician working mainly in discrete mathematics and graph theory. He is considered by many Slovenian mathematicians to be the "father of Slovenian discrete mathematics." [1]

Contents

Biography

As a high school student, Pisanski competed in the 1966 and 1967 International Mathematical Olympiads as a member of the Yugoslav team, winning a bronze medal in 1967. [2] He studied at the University of Ljubljana where he obtained a B.Sc, M.Sc and PhD in mathematics. His 1981 PhD thesis in topological graph theory was written under the guidance of Torrence Parsons. He also obtained an M.Sc. in computer science from Pennsylvania State University in 1979. [3]

Currently, Pisanski is a professor of discrete and computational mathematics and Head of the Department of Information Sciences and Technology at University of Primorska in Koper. [4] In addition, he is a Professor at the University of Ljubljana Faculty of Mathematics and Physics (FMF). He has been a member of the Institute of Mathematics, Physics and Mechanics (IMFM) in Ljubljana since 1980, and the leader of several IMFM research projects. [5] In 1991 he established the Department of Theoretical Computer Science at IMFM, of which he has served as both head and deputy head.

He has taught undergraduate and graduate courses in mathematics and computer science at the University of Ljubljana, University of Zagreb, University of Udine, University of Leoben, California State University, Chico, Simon Fraser University, University of Auckland and Colgate University. [6] Pisanski has been an adviser for M.Sc and PhD students in both mathematics and computer science. Notable students include John Shawe-Taylor (B.Sc in Ljubljana), Vladimir Batagelj, Bojan Mohar, Sandi Klavžar, and Sandra Sattolo (M.Sc in Udine).

Research

Pisanski’s research interests span several areas of discrete and computational mathematics, including combinatorial configurations, abstract polytopes, maps on surfaces, chemical graph theory, and the history of mathematics and science. In 1980 he calculated the genus of the Cartesian product of any pair of connected, bipartite, d-valent graphs using a method that was later called the White–Pisanski method. [7] In 1982 Vladimir Batagelj and Pisanski proved that the Cartesian product of a tree and a cycle is Hamiltonian if and only if no degree of the tree exceeds the length of the cycle. They also proposed a conjecture concerning cyclic Hamiltonicity of graphs. Their conjecture was proved in 2005. [8] With Brigitte Servatius he is the co-author of the book Configurations from a Graphical Viewpoint (2013). [9]

Selected publications

Professional life

From 1998-1999, Pisanski was chairman of the Society of Mathematicians, Physicists and Astronomers of Slovenia (DMFA Slovenije); he was appointed an honorary member in 2015. [10] He is a founding member of the International Academy of Mathematical Chemistry, serving as its Vice President from 2007-2011. [11] In 2008, together with Dragan Marušič, he founded Ars Mathematica Contemporanea, the first international mathematical journal to be published in Slovenia. [12] In 2012 he was elected to the Academia Europaea. [13] He is currently president of the Slovenian Discrete and Applied Mathematics Society (SDAMS), the first Eastern European mathematical society not wholly devoted to theoretical mathematics to be accepted as a full member of the European Mathematical Society (EMS). [14]

Awards and honors

In 2005, Pisanski was decorated with the Order of Merit (Slovenia), [15] and in 2015 he received the Zois award for exceptional contributions to discrete mathematics and its applications. [16] In 2016, he received the Donald Michie and Alan Turing Prize for lifetime achievements in Information Science in Slovenia. [17]

Related Research Articles

Vladimir Batagelj Slovenian mathematician

Vladimir Batagelj is a Slovenian mathematician and an emeritus professor of mathematics at the University of Ljubljana. He is known for his work in discrete mathematics and combinatorial optimization, particularly analysis of social networks and other large networks.

Dragan Marušič Slovenian mathematician

Dragan Marušič is a Slovene mathematician. Marušič obtained his BSc in technical mathematics from the University of Ljubljana in 1976, and his PhD from the University of Reading in 1981 under the supervision of Crispin Nash-Williams.

Levi graph

In combinatorial mathematics, a Levi graph or incidence graph is a bipartite graph associated with an incidence structure. From a collection of points and lines in an incidence geometry or a projective configuration, we form a graph with one vertex per point, one vertex per line, and an edge for every incidence between a point and a line. They are named for Friedrich Wilhelm Levi, who wrote about them in 1942.

Toroidal graph

In mathematics, a toroidal graph is a graph that can be embedded on a torus. In other words, the graph's vertices can be placed on a torus such that no edges cross.

Gray graph

In the mathematical field of graph theory, the Gray graph is an undirected bipartite graph with 54 vertices and 81 edges. It is a cubic graph: every vertex touches exactly three edges. It was discovered by Marion C. Gray in 1932 (unpublished), then discovered independently by Bouwer 1968 in reply to a question posed by Jon Folkman 1967. The Gray graph is interesting as the first known example of a cubic graph having the algebraic property of being edge but not vertex transitive.

Cartesian product of graphs

In graph theory, the Cartesian productGH of graphs G and H is a graph such that

Geometric graph theory

Geometric graph theory in the broader sense is a large and amorphous subfield of graph theory, concerned with graphs defined by geometric means. In a stricter sense, geometric graph theory studies combinatorial and geometric properties of geometric graphs, meaning graphs drawn in the Euclidean plane with possibly intersecting straight-line edges, and topological graphs, where the edges are allowed to be arbitrary continuous curves connecting the vertices, thus it is "the theory of geometric and topological graphs".

Unit distance graph

In mathematics, and particularly geometric graph theory, a unit distance graph is a graph formed from a collection of points in the Euclidean plane by connecting two points by an edge whenever the distance between the two points is exactly one. Edges of unit distance graphs sometimes cross each other, so they are not always planar; a unit distance graph without crossings is called a matchstick graph.

Configuration (geometry)

In mathematics, specifically projective geometry, a configuration in the plane consists of a finite set of points, and a finite arrangement of lines, such that each point is incident to the same number of lines and each line is incident to the same number of points.

Hamming graph

Hamming graphs are a special class of graphs named after Richard Hamming and used in several branches of mathematics and computer science. Let S be a set of q elements and d a positive integer. The Hamming graph H(d,q) has vertex set Sd, the set of ordered d-tuples of elements of S, or sequences of length d from S. Two vertices are adjacent if they differ in precisely one coordinate; that is, if their Hamming distance is one. The Hamming graph H(d,q) is, equivalently, the Cartesian product of d complete graphs Kq.

Edge (geometry)

In geometry, an edge is a particular type of line segment joining two vertices in a polygon, polyhedron, or higher-dimensional polytope. In a polygon, an edge is a line segment on the boundary, and is often called a side. In a polyhedron or more generally a polytope, an edge is a line segment where two faces meet. A segment joining two vertices while passing through the interior or exterior is not an edge but instead is called a diagonal.

Moser spindle

In graph theory, a branch of mathematics, the Moser spindle is an undirected graph, named after mathematicians Leo Moser and his brother William, with seven vertices and eleven edges. It is a unit distance graph requiring four colors in any graph coloring, and its existence can be used to prove that the chromatic number of the plane is at least four.

Möbius–Kantor graph

In the mathematical field of graph theory, the Möbius–Kantor graph is a symmetric bipartite cubic graph with 16 vertices and 24 edges named after August Ferdinand Möbius and Seligmann Kantor. It can be defined as the generalized Petersen graph G(8,3): that is, it is formed by the vertices of an octagon, connected to the vertices of an eight-point star in which each point of the star is connected to the points three steps away from it.

In mathematics, there are two competing definitions for a chiral polytope. One is that it is a polytope that is chiral, meaning that it does not have mirror symmetry. By this definition, a polytope that lacks any symmetry at all would be an example of a chiral polytope.

LCF notation

In combinatorial mathematics, LCF notation or LCF code is a notation devised by Joshua Lederberg, and extended by H. S. M. Coxeter and Robert Frucht, for the representation of cubic graphs that contain a Hamiltonian cycle. The cycle itself includes two out of the three adjacencies for each vertex, and the LCF notation specifies how far along the cycle each vertex's third neighbor is. A single graph may have multiple different representations in LCF notation.

Bojan Mohar is a Slovenian and Canadian mathematician, working in graph theory. He is a professor of mathematics at the University of Ljubljana and the holder of a Canada Research Chair in graph theory at Simon Fraser University in Vancouver, British Columbia, Canada.

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Sandi Klavžar(born 5 February 1962) is a Slovenian mathematician working in the area of graph theory and its applications. He is a professor of mathematics at the University of Ljubljana.

Brigitte Irma Servatius is a mathematician specializing in matroids and structural rigidity. She is a professor of mathematics at Worcester Polytechnic Institute, and has been the editor-in-chief of the Pi Mu Epsilon Journal since 1999.

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References

  1. lea. "Elaboration on the expertise, objectives and contributions — Gregas". www.gregas.eu. Retrieved 2019-04-23.
  2. "Pisanski Tomaž - Biografski koledar slovenskih matematikov, fizikov, astronomov". stanislavpirnat.si. Retrieved 2019-04-25.
  3. "Oddelki - UP FAMNIT". www.famnit.upr.si (in Slovenian). Retrieved 2019-04-25.
  4. "Oddelek za teoretično računalništvo — IMFM". www.imfm.si. Retrieved 2019-04-25.
  5. lea. "Tomaž Pisanski — Gregas". www.gregas.eu. Retrieved 2019-04-26.
  6. J.L. Gross and T.W. Tucker, Topological graph theory, Wiley Interscience, 1987
  7. Dimakopoulos, Vassilios V.; Palios, Leonidas; Poulakidas, Athanasios S. (2005). "On the Hamiltonicity of the Cartesian product". Inf. Proc. Lett. 96 (2): 49–53. doi:10.1016/j.ipl.2005.05.016.
  8. Pisanski, Tomaž; Servatius, Brigitte (2013), Configurations from a Graphical Viewpoint, Springer, ISBN   9780817683641 .
  9. "DMFA Slovenije". www.dmfa.si. Retrieved 2019-04-25.
  10. "IAMC". www.iamc-online.org. Retrieved 2019-04-25.
  11. "Slovenska revija med najboljšimi matematičnimi revijami na svetu". primorske novice. 16 June 2016. Retrieved 24 April 2019.
  12. at Academia Europaea, retrieved 2012-10-09.
  13. "Novice". sdams.si (in Slovenian). Retrieved 2019-04-25.
  14. "Order of Merit (Red za zasluge)".
  15. "2015 | Ministrstvo za izobraževanje, znanost in šport". www.mizs.gov.si. Retrieved 2019-04-23.
  16. "IS AWARDS". IS2019. Retrieved 2019-04-25.