Abstract
Modulo a combination of duality, translation duality or Payne integration, every known finite generalized quadrangle except for the Hermitian quadrangles \(\mathcal {H}(4,q^2)\), is an elation generalized quadrangle for which the elation point is a center of symmetry—that is, is a “skew translation generalized quadrangle” (STGQ). In this series of papers, we classify and characterize STGQs. In the first installment of the series, (1) we obtain the rather surprising result that any skew translation quadrangle of finite odd order (s, s) is a symplectic quadrangle; (2) we determine all finite skew translation quadrangles with distinct elation groups (a problem posed by Payne in a less general setting); (3) we develop a structure theory for root elations of skew translation quadrangles which will also be used in further parts, and which essentially tells us that a very general class of skew translation quadrangles admits the theoretical maximal number of root elations for each member, and hence, all members are “central” (the main property needed to control STGQs, as which will be shown throughout); and (4) we show that finite “generic STGQs,” a class of STGQs which generalizes the class of the previous item (but does not contain it by definition), have the expected parameters. We conjecture that the classes of (3) and (4) contain all STGQs.
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Notes
This is a term coined by the author of the present paper. Given a generalized quadrangle \(\Gamma \) of finite order s and with regular point x, the Payne-derived quadrangle with respect to x is a quadrangle \(\mathcal {P}(\Gamma ,x)\) of order \((s - 1,s + 1)\). I define a “Payne integral” of \(\mathcal {P}(\Gamma ,x)\) as any quadrangle \(\Gamma '\) of order s and with regular point \(x'\) for which \(\mathcal {P}(\Gamma ',x') \cong \mathcal {P}(\Gamma ,x)\). Two such integrals do not have to be isomorphic. And \(\int \mathcal {P}(\Gamma ,x)\mathrm{d}x\) denotes the set of all such integrals.
References
Alperin, J.L., Glauberman, G.: Limits of abelian subgroups of finite \(p\)-groups. J. Algebra 203, 533–566 (1998)
Bamberg, J., Glasby, S.P., Swartz, E.: AS-configurations and skew-translation generalised quadrangles. J. Algebra 421, 311–330 (2015)
Bamberg, J., Penttila, T., Schneider, C.: Elation generalized quadrangles for which the number of lines on a point is the successor of a prime. J. Aust. Math. Soc. 85, 289–303 (2008)
Brown, M.R.: Generalized quadrangles of order \((q, q^2)\), \(q\) even, containing \(W(q)\) as a subquadrangle. Geom. Dedic. 56, 299–306 (1995)
Brown, M.R.: Projective ovoids and generalized quadrangles. Adv. Geom. 7, 65–81 (2007)
Chen, X.: On the groups that generate skew translation generalized quadrangles (Unpublished Manuscript) (1990)
Deligne, P.: Congruences sur le nombre de sous-groupes d’ordre \(p^{k}\) dans un groupe fini. Bull. Soc. Math. Belg. 18, 129–132 (1966)
De Winter, S., Thas, K.: Generalized quadrangles admitting a sharply transitive Heisenberg group. Des. Codes Cryptogr. 47, 237–242 (2008)
Ghinelli, D.: Characterization of some 4-gonal configurations of Ahrens–Szekeres type. Eur. J. Comb. 33, 1557–1573 (2012)
Gillam, J.D.: A note on finite metabelian \(p\)-groups. Proc. Am. Math. Soc. 25, 189–190 (1970)
Hachenberger, D.: Groups admitting a Kantor family and a factorized normal subgroup. Des. Codes Cryptogr. 8, 135–143 (1996)
Hiramine, Y.: Automorphisms of \(p\)-groups of semifield type. Osaka J. Math. 20, 735–746 (1983)
Johnson, N.L., Jha, V., Biliotti, M.: Handbook of Finite Translation Planes, Pure and Applied Mathematics (Boca Raton), vol. 289. Chapman & Hall/CRC, Boca Raton (2007)
Mann, A.: Groups with few class sizes and the centralizer equality subgroup. Israel J. Math. 142, 367–380 (2004)
Knarr, N.: Polar spaces, BLT-sets and generalized quadrangles. Adv. Geom. 8, 139–152 (2008)
Parker, C., Rowley, P.: Quadratic functions and \(GF(q)\)-groups. Proc. Am. Math. Soc. 125, 2227–2237 (1997)
Payne, S.E.: An essay on skew translation generalized quadrangles. Geom. Dedicata 32, 93–118 (1989)
Payne, S.E.: Lecture at Finite Geometries, Groups and Computation. Pingree Park (2004)
Payne, S.E., Thas, J.A.: Finite Generalized Quadrangles, Research Notes in Mathematics, vol. 110. Pitman Advanced Publishing Program, Boston (1984)
Payne, S.E., Thas, J.A.: Finite Generalized Quadrangles, Second edition, EMS Series of Lectures in Mathematics, European Mathematical Society (2009)
Payne, S.E., Thas, K.: Notes on elation generalized quadrangles. Eur. J. Combin. 24, 969–981 (2003)
Penttila, T., Praeger, C.E.: Ovoids and translation ovals. J. Lond. Math. Soc. 56, 607–624 (1997)
Rostermundt, R.: Elation groups of the Hermitian surface \(H(3, q^2)\) over a finite field of characteristic 2. Innov. Incid. Geom. 5, 117–128 (2007)
Stroth, G.: Quadratic forms and special \(2\)-groups. Arch. Math. 33, 415–422 (1979/1980)
Thas, J.A.: Ovoidal translation planes. Arch. Math. 23, 110–112 (1972)
Thas, J.A.: Generalized quadrangles and flocks of cones. Eur. J. Combin. 8, 441–452 (1987)
Thas, J.A.: Generalized quadrangles of order \((s, s^2)\), III. J. Comb. Theory Ser. A 87, 247–272 (1999)
Thas, K.: On symmetries and translation generalized quadrangles. In: Blokhuis, A. et al. (eds.) Finite Geometries, Developments in Mathematics 3, Proceedings of the Fourth Isle of Thorns Conference ‘Finite Geometries’, 16–21 July 2000, pp. 333–345. Kluwer Academic Publishers (2001)
Thas, K.: A theorem concerning nets arising from generalized quadrangles with a regular point. Des. Codes Cryptogr. 25, 247–253 (2002)
Thas, K.: The classification of generalized quadrangles with two translation points. Beiträge Algebra Geom. 43, 365–398 (2002)
Thas, K.: On translation generalized quadrangles for which the translation dual arises from a flock. Glasg. Math. J. 45, 457–474 (2003)
Thas, K.: Symmetry in Finite Generalized Quadrangles, Frontiers in Mathematics, vol. 1. Birkhäuser, Basel (2004)
Thas, K.: Some basic questions and open problems in the theory of elation generalized quadrangles, and their solutions. Bull. Belg. Math. Soc. Simon Stevin 12, 909–918 (2006)
Thas, K.: A question of Kantor on translation quadrangles. Adv. Geom. 7, 375–378 (2007)
Thas, K.: Solution of a question of Knarr. Proc. Am. Math. Soc. 136, 1409–1418 (2008)
Thas, K.: Order in building theory. In: Surveys in Combinatorics 2011, London Math. Soc. Lecture Note Ser., vol. 392, pp. 235–331, Cambridge University Press, Cambridge (2011)
Thas, K.: Generalized quadrangles from a local point of view. J. Geom. 101, 223–238 (2011)
Thas, K.: A Course on Elation Quadrangles, EMS Series of Lectures in Mathematics, European Math. Soc (2012)
Thas, K.: Isomorphisms of groups related to flocks. J. Algebr. Comb. 36, 111–121 (2012)
Thas, K.: Classification of skew translation generalized quadrangles, I. Discrete Math. Theor. Comput. Sci. 17, 89–96 (2015)
Thas, K., Payne, S.E.: Foundations of elation generalized quadrangles. Eur. J. Comb. 27, 51–61 (2006)
Tits, J.: Buildings of Spherical Type and Finite BN-Pairs, Lecture Notes in Mathematics, vol. 386. Springer, Berlin (1974)
Tits, J., Weiss, R.M.: Moufang Polygons, Springer Monographs in Mathematics. Springer, Berlin (2002)
Van Maldeghem, H.: Generalized Polygons, Monographs in Mathematics, vol. 93. Birkhäuser-Verlag, Basel (1998)
Acknowledgements
I presented some of the main results of this paper as a series of (then partly conjectural) results in a lecture, at the conference “Buildings and Groups” (Ghent, May 2007), which was organized by Peter Abramenko, Bernhard Mühlherr and Hendrik Van Maldeghem. Some of the ideas presented at that conference were developed when I was hosted, together with S. De Winter and E. E. Shult, by the Mathematisches Forschungsinstitut Oberwolfach (MFO) in the Research in Pairs program (April 2007). A short synopsis of the chronology can be found in the note [40]. I want to thank an anonymous referee for a number of helpful comments and suggestions on a draft of this paper. Finally, I wish to thank Stanley E. Payne for sending me numerous remarks and questions, which helped me to put the paper into its final shape.
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Dedicated to my dear friend Ernie Shult.
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Thas, K. Central aspects of skew translation quadrangles, 1. J Algebr Comb 48, 429–479 (2018). https://doi.org/10.1007/s10801-017-0801-3
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DOI: https://doi.org/10.1007/s10801-017-0801-3
Keywords
- Generalized quadrangle
- Automorphism group
- Skew translation quadrangle
- Root elation
- Symplectic quadrangle
- Subquadrangle
- Classification
- Characterization