ERGÜN YALÇIN

Professor of Mathematics
Bilkent University

My short CV and current picture.

Course Webpages

Math220-Linear Algebra

Personal Information

Education, mailing address, and long CV

Research Interests

Cohomology of groups,
Group actions on topological spaces,
Homological algebra.

Lecture Notes and Talks

  • Lecture Notes on Group Cohomology (Part 1) (Part 2)
  • Lecture Notes on Rank Conjectures in Topology for (Z/p)^r-actions (link)

    • Publications

    1. On some examples of group actions and group extensions, (with A. Adem),
      J. Group Theory 2 (1999), 69-79.
    2. Group actions and group extensions,
      Trans. of A.M.S. 352 (2000), 2689-2700.
    3. Free p-group actions on products of lens spaces,
      Proc. of A.M.S. 129 (2001), 887-898.
    4. On commuting and non-commuting complexes, (with J. Pakianathan),
      J. Algebra 236 (2001), 396-418.
    5. Set covering and Serre's theorem on the cohomology algebra of a p-group,
      J. Algebra 245 (2001), 50-67.
    6. On nilpotent ideals in the cohomology ring of a finite group, (with J. Pakianathan),
      Topology 42 (2003), 1155-1183.
    7. A new notion of rank for finite supersolvable groups and free linear actions on products of spheres, (with L. Barker),
      J. Group Theory 6 (2003), 347-364.
    8. An induction theorem for the unit groups of Burnside rings of 2-groups
      J. Algebra 289 (2005), 105-127.
    9. A theorem of Jon F. Carlson on filtrations of modules, (with F. Altunbulak),
      J. Pure and Appl. Algebra 208 (2007), 15-28.
    10. Generalized Burnside rings and group cohomology, (with R. Hartmann),
      J. Algebra 310 (2007), 917-944.
    11. Borel-Smith functions and the Dade group, (with S. Bouc),
      J. Algebra 311 (2007), 821-839.
    12. Quadratic maps and Bockstein closed group extensions, (with J. Pakianathan),
      Trans. Amer. Math. Soc. 359 (2007), 6079-6110.
    13. Linear colorings of simplicial complexes and collapsing, (with Y. Civan),
      J. Combin. Theory Ser. A 114 (2007), 1315-1331.
    14. A note on Serre's theorem in group cohomology,
      Proc. Amer. Math. Soc. 136 (2008), 2655-2663.
    15. A Tate cohomology sequence for generalized Burnside rings, (with O. Coşkun)
      J. Pure and Appl. Algebra 213 (2009), 1306-1315.
    16. The Euler class of a subset complex , (with A. Guclukan)
      Quart. J. Math. 61 (2010), 43-68.
    17. Quasilinear actions on products of spheres, (with O. Unlu)
      Bull. London Math. Soc. 42 (2010), 981-990.
    18. Acyclic chain complexes over the orbit category, (with I. Hambleton)
      Munster J. of Math. 3 (2010), 145-162.
    19. Productive elements in group cohomology,
      Homology Homotopy Appl. 13 (2011), 381-401.
    20. Fusion systems and constructing free actions on products of spheres, (with O. Unlu)
      Math. Z. 270 (2012), 939-959.
    21. Bockstein closed 2-group extensions and cohomology of quadratic maps, (with J. Pakianathan)
      J. Algebra 357 (2012), 34-60.
    22. Equivariant CW-complexes and the orbit category, (with I. Hambleton and S. Pamuk)
      Comment. Math. Helv. 88 (2013), 369-425.
    23. Fusion systems and group actions with abelian isotropy subgroups, (with O. Unlu)
      Proc. Edin. Math. Soc. 56 (2013), 873-886.
    24. Free actions on products of spheres at high dimensions, (with O. B. Okutan)
      Algebraic & Geometric Topology 13 (2013), 2087-2099.
    25. Constructing homologically trivial actions on products of spheres, (with O. Unlu)
      Indiana Univ. Math. J. 62 (2013), 927-945.
    26. Relative group cohomology and the orbit category, (with S. Pamuk)
      Communications in Algebra 42 (2014), 3220-3243.
    27. Homotopy representations over the orbit category, (with I. Hambleton)
      Homology Homotopy Appl. 16 (2014), 345-369.
    28. On the basis of the Burnside ring of a fusion system, (with M. Gelvin and S. P. Reeh)
      J. Algebra 423 (2015), 767-797.
    29. Group actions on spheres with rank one isotropy, (with I. Hambleton)
      Trans. Amer. Math. Soc. 368 (2016), 5951-5977.
    30. Rank Three p-Group Actions on Products of Spheres,
      Bull. London Math. Soc. 48 (2016), 325-340.
    31. Group actions on spheres with rank one prime power isotropy, (with I. Hambleton)
      Math. Res. Letters 24 (2017), 379-400.
    32. Equivariant Moore spaces and the Dade group,
      Adv. Math. 309 (2017), 209-237.
    33. Representation rings for fusion systems and dimension functions, (with S.P. Reeh)
      Math. Z. 288 (2018), 509-530.
    34. Dimension functions for spherical fibrations, (with C. Okay)
      Algebraic & Geometric Topology 18 (2018), 3907-3941.
    35. Obstructions for gluing biset functors, (with O. Coşkun)
      J. Algebra 532 (2019), 268-310.
    36. Cohomology of infinite groups realizing fusion systems, (with M. S. Gundogan)
      Journal of Homotopy and Related Structures 14 (2019), 1103-1130.
    37. Finite groups of rank two which do not involve Qd(p), (with M. Y. Kizmaz)
      Proc. Amer. Math. Soc. 148 (2020), 3713-3721.
    38. Dade groups for finite groups and dimension functions, (with M. Gelvin)
      J. Algebra 576 (2021), 146-196.
    39. Higher limits over the fusion orbit category,
      Adv. Math. 406 (2022) 108482, 69 pp.
    40. LHS-spectral sequences for regular extensions of categories,
      Journal of Homotopy and Related Structures, 19 (2024), 1-51.
    41. Steenrod closed parameter ideals in the mod-2 cohomology of A_4 and SO(3), (with H. Ruping and M. Stephan)
      Journal of Pure and Applied Algebra, 229 (2025) 107899.
    42. Thomason cohomology and Quillen's Theorem A, (with M. Kirtisoglu)
      Applied Categorical Structures (2026) 34:22.
    43. Free Actions on Products of Real Projective Spaces,
      to appear in Algebraic & Geometric Topology, 2026.
    44. Worst-Case Examples for the Computation of Persistent Homology, (with U. Cetin)
      Submitted, 2026.
    45. Equivariant CW-complexes homotopy equivalent to spheres: a survey, (with I. Hambleton)
      to appear in the Proceedings of the Fields focus program honouring Fred Cohen, 2026.

    Subjects Taught

    Undergraduate Level
    Calculus (101, 102, 111, 112)
    Linear Algebra (220, 223, 224, 227)
    Abstract Mathematics (123, 124)
    Advanced Calculus (213, 214)
    Differential Equations (240)
    Introduction to Probability (250)
    Topology (310)
    Algebra (323, 324)
    Discrete Mathematics (110, 132, 210)
    Number Theory (253)

    Graduate Level
    Algebra I, II (523, 524)
    Group Representations (525)
    Homological Algebra (625)
    Algebraic Topology I (611)
    Topics in Algebraic Topology I (618)
    Cohomology of Groups (626)

    Regular Math Meetings

    Office: 127 Science A
    Bilkent University
    Bilkent, Ankara 06800 Turkey
    Phone:
    +90 312 290 2115
    Fax:
    +90 312 290 5097
    Email: yalcine \at fen \dot bilkent \dot edu \dot tr

    Last update: August 21, 2026