Tomaž (Tomo) Pisanski (born 24 May 1949 in

Ljubljana {{Infobox settlement , name = Ljubljana , official_name = , settlement_type = Capital city , image_skyline = {{multiple image , border = infobox , perrow = 1/2/2/1 , total_widt ...

Yugoslavia , common_name = Yugoslavia , life_span = 1918–19921941–1945: World War II in Yugoslavia#Axis invasion and dismemberment of Yugoslavia, Axis occupation , p1 = Kingdom of SerbiaSerbia , flag_p ...

, which is now in

Slovenia Slovenia, officially the Republic of Slovenia, is a country in Central Europe. It borders Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the south and southeast, and a short (46.6 km) coastline within the Adriati ...

) is a

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

working mainly in

discrete mathematics Discrete mathematics is the study of mathematical structures that can be considered "discrete" (in a way analogous to discrete variables, having a bijection with the set of natural numbers) rather than "continuous" (analogously to continuous f ...

and

graph theory In mathematics and computer science, graph theory is the study of ''graph (discrete mathematics), graphs'', which are mathematical structures used to model pairwise relations between objects. A graph in this context is made up of ''Vertex (graph ...

. He is considered by many Slovenian mathematicians to be the "father of Slovenian discrete mathematics."

Biography

As a high school student, Pisanski competed in the 1966 and 1967

International Mathematical Olympiad The International Mathematical Olympiad (IMO) is a mathematical olympiad for pre-university students, and is the oldest of the International Science Olympiads. It is widely regarded as the most prestigious mathematical competition in the wor ...

s as a member of the Yugoslav team, winning a bronze medal in 1967. He studied at the

University of Ljubljana The University of Ljubljana (, , ), abbreviated UL, is the oldest and largest university in Slovenia. It has approximately 38,000 enrolled students. The university has 23 faculties and three art academies with approximately 4,000 teaching and re ...

where he obtained a B.Sc, M.Sc and PhD in mathematics. His 1981 PhD thesis in

topological graph theory In mathematics, topological graph theory is a branch of graph theory. It studies the embedding of graphs in surfaces, spatial embeddings of graphs, and graphs as topological spaces. It also studies immersions of graphs. Embedding a graph in ...

was written under the guidance of Torrence Parsons. He also obtained an M.Sc. in

computer science Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, ...

from

Pennsylvania State University The Pennsylvania State University (Penn State or PSU) is a Public university, public Commonwealth System of Higher Education, state-related Land-grant university, land-grant research university with campuses and facilities throughout Pennsyl ...

in 1979. Currently, Pisanski is a professor of

discrete Discrete may refer to: *Discrete particle or quantum in physics, for example in quantum theory * Discrete device, an electronic component with just one circuit element, either passive or active, other than an integrated circuit * Discrete group, ...

and

computational mathematics Computational mathematics is the study of the interaction between mathematics and calculations done by a computer.National Science Foundation, Division of Mathematical ScienceProgram description PD 06-888 Computational Mathematics 2006. Retri ...

and Head of the Department of Information Sciences and Technology at

University of Primorska University of Primorska ( Slovenian ''Univerza na Primorskem'', Italian ''Università del Litorale'') is a public university in Slovenia. It is located in Koper, Izola, and Portorož and is named for the Slovenian Littoral region, where it i ...

Koper Koper (; ) is the List of cities and towns in Slovenia, fifth-largest city in Slovenia. Located in the Slovenian Istria, Istrian region in the southwestern part of the country, Koper is the main urban center of the Slovene coast. Port of Koper i ...

. In addition, he is a professor at the

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. 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 Zagreb The University of Zagreb (, ) is a public university, public research university in Zagreb, Croatia. It is the largest Croatian university and one of the oldest continuously operating universities in Europe. The University of Zagreb and the Unive ...

, University of Udine,

University of Leoben The Technical University of Leoben is a public university in Leoben, Styria, Austria. It was established on 4 November 1840 as the ''Steiermärkisch-Ständische Montanlehranstalt'' in Vordernberg, Styria, Austria's mining region. In 1849, Peter ...

, California State University, Chico,

Simon Fraser University Simon Fraser University (SFU) is a Public university, public research university in British Columbia, Canada. It maintains three campuses in Greater Vancouver, respectively located in Burnaby (main campus), Surrey, British Columbia, Surrey, and ...

University of Auckland The University of Auckland (; Māori: ''Waipapa Taumata Rau'') is a public research university based in Auckland, New Zealand. The institution was established in 1883 as a constituent college of the University of New Zealand. Initially loc ...

and

Colgate University Colgate University is a Private university, private college in Hamilton, New York, United States. The Liberal arts colleges in the United States, liberal arts college was founded in 1819 as the Baptist Education Society of the State of New York ...

. 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 polytope In mathematics, an abstract polytope is an algebraic partially ordered set which captures the dyadic property of a traditional polytope without specifying purely geometric properties such as points and lines. A geometric polytope is said to be ...

s, maps on surfaces,

chemical graph theory Chemical graph theory is the topology branch of mathematical chemistry which applies graph theory to mathematical modelling of chemical phenomena. The pioneers of chemical graph theory are Alexandru Balaban, Ante Graovac, Iván Gutman, Haruo ...

, and the history of mathematics and science. In 1980 he calculated the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of the

Cartesian product In mathematics, specifically set theory, the Cartesian product of two sets and , denoted , is the set of all ordered pairs where is an element of and is an element of . In terms of set-builder notation, that is A\times B = \. A table c ...

of any pair of connected, bipartite, ''d''-valent graphs using a method that was later called the ''White–Pisanski method''. In 1982 Vladimir Batagelj and Pisanski proved that the

of a

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

and a cycle is

Hamiltonian Hamiltonian may refer to: * Hamiltonian mechanics, a function that represents the total energy of a system * Hamiltonian (quantum mechanics), an operator corresponding to the total energy of that system ** Dyall Hamiltonian, a modified 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. With Brigitte Servatius he is the co-author of the book ''Configurations from a Graphical Viewpoint'' (2013). .

Selected publications

* Pisanski, T. Genus of Cartesian products of regular bipartite graphs, Journal of Graph Theory 4 (1), 1980, 31-42
doi:10.1002/jgt.3190040105
* Graovac, A., T. Pisanski. On the Wiener index of a graph, Journal of Mathematical Chemistry 8 (1),1991, 53-62
doi:10.1007/BF01166923
* Boben, M., B. Grunbaum, T. Pisanski, A. Zitnik, Small triangle-free configurations of points and lines,

Discrete & Computational Geometry '' Discrete & Computational Geometry'' is a peer-reviewed mathematics journal published quarterly by Springer. Founded in 1986 by Jacob E. Goodman and Richard M. Pollack, the journal publishes articles on discrete geometry and computational ...

35 (3), 2006, 405-427
doi:10.1007/s00454-005-1224-9
* Conder, M., I. Hubard, T. Pisanski. Constructions for chiral polytopes, Journal of the London Mathematical Society 77 (1), 2007, 115-129
doi:10.1112/jlms/jdm093
* Pisanski, T. A classification of cubic bicirculants,

Discrete Mathematics Discrete mathematics is the study of mathematical structures that can be considered "discrete" (in a way analogous to discrete variables, having a bijection with the set of natural numbers) rather than "continuous" (analogously to continuous f ...

307 (3-5), 2007, 567-578
doi:10.1016/j.disc.2005.09.053

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. He is a founding member of the

International Academy of Mathematical Chemistry The International Academy of Mathematical Chemistry (IAMC) was founded in Dubrovnik, Croatia, in 2005 by Milan Randić. It is an organization for chemistry and mathematics avocation; its predecessors have been around since the 1930s. There are 88 ...

, serving as its vice president from 2007 to 2011. In 2008, together with Dragan Marušič, he founded ''

Ars Mathematica Contemporanea ''Ars Mathematica Contemporanea'' is a quarterly peer-reviewed scientific journal covering discrete mathematics in connection with other branches of mathematics. It is published by the University of Primorska together with the Society of Mathematic ...

,'' the first international mathematical journal to be published in Slovenia. In 2012 he was elected to the

Academia Europaea The Academia Europaea is a pan-European Academy of humanities, letters, law, and sciences. The Academia was founded in 1988 as a functioning Europe-wide Academy that encompasses all fields of scholarly inquiry. It acts as co-ordinator of Europe ...

. He was the president of the Slovenian Discrete and Applied Mathematics Society (SDAMS) from its conception until December 12, 2024. SDAMS is the first Eastern European mathematical society not wholly devoted to theoretical mathematics to be accepted as a full member of the

European Mathematical Society The European Mathematical Society (EMS) is a European organization dedicated to the development of mathematics in Europe. Its members are different mathematical societies in Europe, academic institutions and individual mathematicians. The curren ...

(EMS).

Awards and honors

In 2005, Pisanski was decorated with the Order of Merit (Slovenia), and in 2015 he received the Zois award for exceptional contributions to discrete mathematics and its applications. In 2016, he received the

Donald Michie Donald Michie (; 11 November 1923 – 7 July 2007) was a British researcher in artificial intelligence. During World War II, Michie worked for the Government Code and Cypher School at Bletchley Park, contributing to the effort to solve " Tunny ...

and

Alan Turing Alan Mathison Turing (; 23 June 1912 – 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher and theoretical biologist. He was highly influential in the development of theoretical computer ...

Prize for lifetime achievements in Information Science in Slovenia.

References

External links

Pisanski's CV
* *

* ttp://en.ias.si/membership/regular-and-associate-members/ Slovenian Academy of Engineering - List of Membersbr>Images of Knowledge: Tomaž Pisanski - RTV radio interview8th European Congress of Mathematics websiteMaps ∩ Configurations ∩ Polytopes ∩ Molecules ⊆ Graphs: The mathematics of Tomaž Pisanski on the occasion of his 70th birthdayArs Mathematica Contemporanea websiteSlovenian Society for Discrete and Applied Mathematics (SDAMS) website
{{DEFAULTSORT:Pisanski, Tomaz 1949 births 20th-century Slovenian mathematicians 21st-century Slovenian mathematicians Graph theorists Living people Pennsylvania State University alumni Slovenian computer scientists Scientists from Ljubljana Mathematical chemistry University of Ljubljana alumni Members of Academia Europaea Academic staff of the University of Ljubljana Academic staff of the University of Primorska Academic staff of the University of Zagreb Academic staff of Montanuniversität Leoben California State University, Chico faculty Academic staff of Simon Fraser University Academic staff of the University of Auckland Colgate University faculty International Mathematical Olympiad participants Computational chemists Yugoslav mathematicians