Loop characters
Johnson, Kenneth Walter
Commentationes Mathematicae Universitatis Carolinae, Tome 41 (2000), p. 271-281 / Harvested from Czech Digital Mathematics Library

A survey of the basic results of loop characters is given on the lines of the treatment of the author and J.D.H. Smith for characters of quasigroups, including some recent deveploments. One of the successes of the theory has been its suggestive influence on the theory of association schemes, group representations and the theory of the group determinant, and selected results arising are described. A section is devoted to an explanation of how the tool of loop characters has not yet been as startlingly successful as that of the early theory of group characters. This may be because in the loop case more is needed than characters and some suggestions are put forward in this direction.

Publié le : 2000-01-01
Classification:  05E30,  19A22,  20C99,  20N05
@article{119163,
     author = {Kenneth Walter Johnson},
     title = {Loop characters},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     volume = {41},
     year = {2000},
     pages = {271-281},
     zbl = {1038.20048},
     mrnumber = {1780871},
     language = {en},
     url = {http://dml.mathdoc.fr/item/119163}
}
Johnson, Kenneth Walter. Loop characters. Commentationes Mathematicae Universitatis Carolinae, Tome 41 (2000) pp. 271-281. http://gdmltest.u-ga.fr/item/119163/

Bannai E.; Ito T. Algebraic Combinatorics I., Benjamin-Cummings Lecture Notes Series No. 58, Menlo Park, California, 1994. | MR 0882540 | Zbl 0685.05030

Bannai E.; Song S. The character tables of Paige's simple Moufang loops and their relationship to the character tables of PSL$(2,q)$, Proc. London Math. Soc. (3) 58 (1989), 209-236. (1989) | MR 0977475 | Zbl 0682.20050

Bannai E.; Kawanaka N.; Song S. The character table of the Hecke algebra ${\Cal H}({GL}_{2n}(F_ q),{Sp}_ {2n} (F_ q))$, J. Algebra 129 (1990), 320-366. (1990) | MR 1040942

Bannai E.; Hao S.; Song S. Character tables of the association schemes of finite orthogonal groups acting on the nonisotropic points, J. Combin. Theory Ser. A 54 (1990), 164-200. (1990) | MR 1059994 | Zbl 0762.20005

Brauer R. Representations of finite groups, in Lectures in Modern Mathematics, Vol. 1, T.L. Saaty (ed.), Wiley, 1963, pp.133-175. | MR 0178056 | Zbl 0333.20008

Cameron P.J.; Kiyota M. Sharp characters of finite groups, J. Algebra 115 (1988), 125-143. (1988) | MR 0937604 | Zbl 0651.20010

Godsil C.D. Algebraic Combinatorics, Chapman & Hall, New York, 1993. | MR 1220704 | Zbl 0814.05075

Formanek E.; Sibley D. The group determinant determines the group, Proc. Amer. Math. Soc 112 (1991), 649-656. (1991) | MR 1062831 | Zbl 0742.20008

Frobenius G. Über Gruppencharaktere, Sitzungsber. Preuss. Akad. Wiss. Berlin (1896), 985-1021. (Gesammelte Abhandlungen, (Springer-Verlag 1968), pp.1-37).

Johnson K.W. Latin square determinants, in Algebraic, Extremal and Metric Combinatorics 1986, London Math. Soc. Lecture Notes 131, 1988, pp.146-154. | MR 1052664 | Zbl 0761.05019

Johnson K.W. Some historical aspects of the development of group representation theory and its extension to quasigroups, Universal Algebra and Quasigroup Theory, A. Romanowska, J.D.H. Smith (eds.) Heldermann Verlag, Berlin, 1992, pp.101-117. | MR 1191229

Johnson K.W. Latin square determinants II., Discrete Math. 105 (1992), 111-130. (1992) | MR 1180197 | Zbl 0761.05019

Johnson K.W. Sharp characters of quasigroups, European J. Combin. 14 (1993), 103-112. (1993) | MR 1206615 | Zbl 0773.20030

Johnson K.W. The Dedekind-Frobenius group determinant, new life in an old method, Proceedings of the Groups 97 Conference, Bath, England 1997; London Math. Soc. Lecture Notes 261, 1999, pp.417-428. | MR 1676638

Johnson K.W.; Ford D. Determinants of latin squares of order $8$, Experimental Math. 5 (1996), 317-325. (1996) | MR 1437221 | Zbl 0876.05017

Johnson K.W.; Mattarei S.; Sehgal S.K. Weak Cayley tables, to appear in J. London Math. Soc. | Zbl 0962.20003

Johnson K.W.; Poimenidou E. Generalised classes in groups and association schemes, duals of results on characters and sharpness, European J. Combin. 20 (1999), 1-6. (1999) | MR 1669612 | Zbl 0916.05075

Johnson K.W.; Smith J.D.H. Characters of finite quasigroups, European J. Combin. 5 (1984), 43-50. (1984) | MR 0746044 | Zbl 0537.20042

Johnson K.W.; Smith J.D.H. Characters of finite quasigroups II: induced characters, European J. Combin. 7 (1986), 131-138. (1986) | MR 0856325 | Zbl 0599.20110

Johnson K.W.; Smith J.D.H. Characters of finite quasigroups III, Quotients and fusion, European J. Combin. 10 (1989), 47-56. (1989) | MR 0977179 | Zbl 0667.20053

Johnson K.W.; Smith J.D.H. Characters of finite quasigroups IV: products and superschemes, European J. Combin. 10 (1989), 257-263. (1989) | MR 1029172 | Zbl 0669.20053

Johnson K.W.; Smith J.D.H. Characters of finite quasigroups V: linear characters, European J. Combin. 10 (1989), 449-456. (1989) | MR 1014553 | Zbl 0679.20059

Johnson K.W.; Smith J.D.H. A note on the induction of characters in association schemes, European J. Combin. 7 (1986), 139-140. (1986) | MR 0856326

Johnson K.W.; Song S-Y.; Smith J.D.H. Characters of finite quasigroups VI: critical examples, European J. Combin. 11 (1990), 267-275. (1990) | MR 1059557 | Zbl 0704.20056

Mackey G.W. Harmonic analysis as an exploitation of symmetry - a historical survey, Bull. Amer. Math. Soc. 3 (1980), 543-698. (1980) | MR 0571370

Smith J.D.H. Combinatorial characters of quasigroups, in Coding Theory and Design Theory, Part I: Coding Theory, (D. Ray-Chaudhuri, ed.) Springer, New York, 1990. | MR 1047879 | Zbl 0708.20021

Smith J.D.H. Quasigroup actions: Markov chains, pseudoinverses, and linear transformations, to appear in South-East Asian Bulletin of Mathematics.

Smith J.D.H. Quasigroup representation theory. Universal Algebra and Quasigroup Theory, A. Romanowska, J.D.H. Smith (eds.), Heldermann, Berlin, 1992, pp.195-207. | MR 1191234

Song S-Y. Fusion relations in products of association schemes, preprint. | MR 1939083