Alexander Schrijver (= Lex Schrijver)
Mailing and visiting address:
CWI,
Science Park 123,
1098 XG Amsterdam, Netherlands.

(Same location as formerly Kruislaan 413, street has only been renamed and renumbered. Google maps still calls it Kruislaan 413.)

email: lex@cwi.nl
phone numbers: +31-20-592 4087 (office), +31-20-592 4189 (secretary), +31-20-592 9333 (reception)
fax: +31-20-592 4199

how to reach CWI (Note however that Amstel Station is not the nearest station, but Muiderpoort Station is, and might be preferable if coming from the North or East of the Netherlands.
From Muiderpoort Station, walk 15 minutes or take bus 40.)
Google map (Kruislaan 413 = Science Park 123)
home-page of CWI (Center for Mathematics and Computer Science)

Ignatius Prijsvraag: PDF
NEMO Prijsvraag: PDF
Paradiso Prijsvraag: PDF

Preprints:
Railway optimization / Spoorwegoptimalisering:
Course notes:
Block diagonalization of matrix *-algebras PS PDF
A Course in Combinatorial Optimization PS PDF
Worksheets: Exercise 4.8 (i) PS PDF Exercise 4.8 (ii) PS PDF Exercise 4.8 (iii) PS PDF Exercise 4.8 (iv) PS PDF

Grafen: Kleuren en Routeren PS PDF

Course "Advanced Graph Theory and Combinatorial Optimization" spring 2001:
lecture notes PS PDF

Proof of the Tutte-Berge formula PS PDF

Proof of Vizing's theorem PS PDF

Maximum flow PS PDF

Cliques, stable sets, and colourings PS


Master Course "Advanced Graph Theory"
spring 2009, by Rudi Pendavingh and Lex Schrijver:
Tuesdays 14:00--16:00 from 3 February 2009, at University of Amsterdam,
Plantage Muidergracht 24, 1018 TV Amsterdam, Room P.019.
See mastermath webside.
The results of the exam of June 2 are available from June 10 on. To know your result, send an email to lex@cwi.nl.
The re-exam is on Tuesday 23 June 2009 14:00-17:00 at Plantage Muidergracht 24, 1018 TV Amsterdam, Room P.018 (only for those who participated in the first exam).
The results of the re-exam of June 23 are available from July 3 on. To know your result, send an email to lex@cwi.nl.
Lecture Notes:
  • I. Matchings and coverings
  • II. Stable sets and colourings
  • III. Disjoint paths

    • Book: Combinatorial Optimization - Polyhedra and Efficiency (Springer-Verlag, Berlin, 2003):
    Table of Contents PS PDF

    Survey of Problems, Questions, and Conjectures PS PDF

    Comments welcome at lex@cwi.nl
    Further Information from Springer-Verlag Heidelberg
    Further Information from Springer-Verlag New York
    The book now is also available on CD-ROM from Springer-Verlag

    Recent publications:
    • L. Lov\'asz, A. Schrijver, Dual graph homomorphism functions, Journal of Combinatorial Theory, Series A 117 (2010) 216--222. PDF
    • L. Lov\'asz, A. Schrijver, Semidefinite functions on categories, The Electronic Journal of Combinatorics 16(2) 2009 R14. PDF (preprint), PDF
    • A. Schrijver, Graph invariants in the spin model, Journal of Combinatorial Theory, Series B 99 (2009) 502--511. PDF
    • L.G. Kroon, D. Huisman, E. Abbink, P.J. Fioole, M. Fischetti, G. Mar\'oti, A. Schrijver, A. Steenbeek, The new Dutch timetable: The OR revolution, Interfaces 39 (2009) 6--17. PDF
    • L.G. Kroon, R.M. Lentink, A. Schrijver, Shunting of passenger train units: an integrated approach, Transportation Science 42 (2008) 436--449. PDF
    • A. Schrijver, Wiskunde achter het spoorboekje, Pythagoras 48 (2) (2008) 8--12. PDF
    • A. Schrijver, Graph invariants in the edge model. in: ``Building Bridges --- Between Mathematics and Computer Science'' (M. Gr\"otschel, G.O.H. Katona, eds.), Springer, Berlin, 2008, pp. 487--498. PS PDF
    • A. Schrijver, Flows in railway optimization, Nieuw Archief voor Wiskunde (3) 9 (2008) 126--131. PDF
    • L. Lov\'asz, A. Schrijver, Graph parameters and semigroup functions, European Journal of Combinatorics 29 (2008) 987--1002. PS PDF
    • A. Schrijver, Szemelv\'enyek a kombinatorikus optimaliz\'al\'as t\"ort\'enet\'eb\"ol, Alkalmazott Matematikai Lapok 25 (2008) 1--74.
    • \'E. Colin de Verdi\`ere, A. Schrijver, Shortest vertex-disjoint two-face paths in planar graphs, in: 25th International Symposium on Theoretical Aspects of Computer Science (STACS 2008), pp. 181--192. PDF
    • A. Schrijver, Tensor subalgebras and first fundamental theorems in invariant theory, Journal of Algebra 319 (2008) 1305--1319. PS PDF
    • E. de Klerk, D.V. Pasechnik, A. Schrijver, Reduction of symmetric semidefinite programs using the regular $*$-representation, Mathematical Programming, Series B 109 (2007) 613--624. PS PDF
    • M.H. Freedman, L. Lov\'asz, A. Schrijver, Reflection positivity, rank connectivity, and homomorphisms of graphs, Journal of the American Mathematical Society 20 (2007) 37--51. PDF
    • H. Buhrman, R. Cleve, M. Laurent, N. Linden, A. Schrijver, F. Unger, New limits on fault-tolerant quantum computation, in: 47th Annual IEEE Symposium on Foundations of Computer Science (FOCS'06), pp. 411--419. PS
    • P.J. Fioole, L.G. Kroon, G. Mar\'oti, A. Schrijver, A rolling stock circulation model for combining and splitting of passenger trains, European Journal of Operational Research 174 (2006) 1281--1297. PS PDF
    • D. Gijswijt, A. Schrijver, H. Tanaka, New upper bounds for nonbinary codes based on the Terwilliger algebra and semidefinite programming, Journal of Combinatorial Theory, Series A 113 (2006) 1719--1731. PS
    • A. Alfieri, R. Groot, L. Kroon, A. Schrijver, Efficient circulation of railway rolling stock, Transportation Science 40 (2006) 378--391. PDF
    • A. Schrijver, New code bounds with noncommutative algebra, Oberwolfach Reports 3 (2006) 9--12. PDF
    • A. Schrijver, On the history of combinatorial optimization (till 1960), in: ``Handbook of Discrete Optimization'' (K. Aardal, G.L. Nemhauser, R. Weismantel, eds.), Elsevier, Amsterdam, 2005, pp. 1--68. PDF
    • C.J. Luz, A. Schrijver, A convex quadratic characterization of the Lov\'asz theta number, SIAM Journal on Discrete Mathematics 19 (2005) 382--387. PDF
    • A. Schrijver, New code upper bounds from the Terwilliger algebra and semidefinite programming, IEEE Transactions on Information Theory 51 (2005) 2859--2866. PS PDF
    • A. Schrijver, Polyhedral combinatorics and combinatorial optimization, in: ``Journ\'ee Annuelle --- Recherche Op\'erationnelle'', Soci\'et\'e Math\'ematique de France, Paris, 2004, pp. 59--74. PS PDF
    • M.H. Freedman, L. Lov\'asz, A. Schrijver, Graph parameters and reflection positivity, Oberwolfach Reports 1 (2004) 79--81. PS PDF
    • A. Schrijver, Matching, edge-colouring, dimers, in: ``Graph-Theoretic Concepts in Computer Science'' (H.L. Bodlaender, ed.), Lecture Notes in Computer Science 2880, Springer-Verlag, Berlin, 2003, pp. 13--22. PS PDF
    • A.M.H. Gerards, G. Mar\'oti, A. Schrijver, Note on: N.E. Aguilera, M.S. Escalante, G.L. Nasini, ``A generalization of the perfect graph theorem under the disjunctive index'', Mathematics of Operations Research 28 (2003) 884--885.
    • D.C. Gijswijt, A. Schrijver, On the $b$-stable set polytope of graphs without bad $K_4$, SIAM Journal on Discrete Mathematics 16 (2003) 511--516.
    • B. Mohar, A. Schrijver, Blocking nonorientability of a surface, Journal of Combinatorial Theory, Series B 87 (2003) 2--16.
    • A. Schrijver, Strong t-perfection of bad-$K_4$-free graphs, SIAM Journal on Discrete Mathematics 15 (2002) 403--415. PS PDF
    • A. Schrijver, A short proof of Guenin's characterization of weakly bipartite graphs, Journal of Combinatorial Theory, Series B 85 (2002) 255--260. PS PDF
    • A. Schrijver, On the history of the transportation and maximum flow problems, Mathematical Programming 91 (2002) 437--445. PS PDF
    • A. Schrijver, A short proof of Mader's ${\cal S}$-paths theorem, Journal of Combinatorial Theory, Series B 82 (2001) 319--321. PS PDF
    • A. Schrijver, Total dual integrality of matching forest constraints, Combinatorica 20 (2000) 575--588. PS
    • A. Schrijver, A combinatorial algorithm minimizing submodular functions in strongly polynomial time, Journal of Combinatorial Theory, Series B 80 (2000) 346--355. PS PDF
    • J. Keijsper, R. Pendavingh, A. Schrijver, Adjacency, inseparability, and base orderability in matroids, European Journal of Combinatorics 21 (2000) 487--502.
    • J. Koolen, M. Laurent, A. Schrijver, Equilateral dimension of the rectilinear space, Designs, Codes and Cryptography 21 (2000) 149--164.
    • L. Lov\'asz, A. Schrijver, On the null space of a Colin de Verdi\`ere matrix, Annales de l'Institut Fourier 49 (1999) 1017--1026. PS
    • A. Schrijver, Bipartite edge-colouring in $O(\Delta m)$ time, SIAM Journal on Computing 28 (1999) 841--846. PS PDF
    • H. van der Holst, L. Lov\'asz, A. Schrijver, The Colin de Verdi\`ere graph parameter, in: ``Graph Theory and Combinatorial Biology'' (L. Lov\'asz, A. Gy\'arf\'as, G. Katona, A. Recski, L. Sz\'ekely, eds.), J\'anos Bolyai Mathematical Society, Budapest, 1999, pp. 29--85. PS PDF
    • S. van Vlijmen, S. Klusener, A. Schrijver, The compact dynamic bus station, Electronic Notes in Theoretical Computer Science Vol. 21 No. 7, Elsevier, Amsterdam, 1999.
    • A. Schrijver, P. Seymour, P. Winkler, The ring loading problem, SIAM Review 41 (1999) 777--791. PS PDF
    • A. Schrijver, Counting $1$-factors in regular bipartite graphs, Journal of Combinatorial Theory, Series B 72 (1998) 122--135. PS PDF
    • L. Lov\'asz, A. Schrijver, A Borsuk theorem for antipodal links and a spectral characterization of linklessly embeddable graphs, Proceedings of the American Mathematical Society 126 (1998) 1275--1285. PS PDF
    • J. Keijsper, A. Schrijver, On packing connectors, Journal of Combinatorial Theory, Series B 73 (1998) 184--188.
    • A. Schrijver, Routing and timetabling by topological search, in: ``International Congress of Mathematicians'' Volume III, Documenta Mathematica, Extra Vol. ICM III, (1998) 687-695. PS PDF
    Further references in MathSciNet for A. Schrijver
    See also the DARE-net repository
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