Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-22T09:13:17.644Z Has data issue: false hasContentIssue false

Set Theory Generated by Abelian Group Theory

Published online by Cambridge University Press:  15 January 2014

Paul C. Eklof*
Affiliation:
Department of Mathematics, University of California, Irvine, Irvine, CA 92697-3875, USA.E-mail: [email protected]

Extract

Introduction. This survey is intended to introduce to logicians some notions, methods and theorems in set theory which arose—largely through the work of Saharon Shelah—out of (successful) attempts to solve problems in abelian group theory, principally the Whitehead problem and the closely related problem of the existence of almost free abelian groups. While Shelah's first independence result regarding the Whitehead problem used established set-theoretical methods (discussed below), his later work required new ideas; it is on these that we focus. We emphasize the nature of the new ideas and the historical context in which they arose, and we do not attempt to give precise technical definitions in all cases, nor to include a comprehensive survey of the algebraic results.

In fact, very little algebraic background is needed beyond the definitions of group and group homomorphism. Unless otherwise specified, we will use the word “group” to refer to an abelian group, that is, the group operation is commutative. The group operation will be denoted by +, the identity element by 0, and the inverse of a by −a. We shall use na as an abbreviation for a + a + … + a [n times] if n is positive, and na = (−n)(−a) if n is negative.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1] Bing, R. H., Metrization of topological spaces, Canadadian Journal of Mathematics, vol. 3 (1951), pp. 175186.Google Scholar
[2] Chase, S. U., On group extensions and a problem of J. H. C. Whitehead, Topics in abelian groups, Scott, Foresman and Co., 1963, pp. 173197.Google Scholar
[3] Devlin, K. J. and Shelah, S., A weak version of ◊ which follows from 2 0 < 2 1 , Israel Journal of Mathematics, vol. 29 (1978), pp. 239247.Google Scholar
[4] Devlin, K. J. and Shelah, S., A note on the normal Moore space conjecture, Canadian Journal of Mathematics, vol. 31 (1979), pp. 241251.CrossRefGoogle Scholar
[5] Eklof, P. C., Infinitary equivalence of abelian groups, Fundamenta Mathematicae, vol. 81 (1974), pp. 305314.Google Scholar
[6] Eklof, P. C., Whitehead's problem is undecidable, American Mathematical Monthly, vol. 83 (1976), pp. 775788.CrossRefGoogle Scholar
[7] Eklof, P. C., Homological algebra and set theory, Transactions of the American Mathematical Society, vol. 227 (1977), pp. 207225.Google Scholar
[8] Eklof, P. C., Set theoretic methods in homological algebra and abelian groups, Les Presses de L'Université de Montréal, 1980.Google Scholar
[9] Eklof, P. C. and Mekler, A. H., Categoricity results for L∞κ-algebras, Annals of Pure and Applied Logic, vol. 37 (1988), pp. 8199.Google Scholar
[10] Eklof, P. C. and Mekler, A. H., Almost free modules, North-Holland, 1990.Google Scholar
[11] Eklof, P. C. and Shelah, S., On Whitehead modules, Journal of Algebra, vol. 142 (1991), pp. 492510.Google Scholar
[12] Eklof, P. C. and Shelah, S., A combinatorial principle equivalent to the existence of non-free Whitehead groups, Contemporary Mathematics, vol. 171 (1994), pp. 7998.Google Scholar
[13] Fleissner, W., Normal Moore spaces in the constructible universe, Proceedings of the American Mathematical Society, vol. 46 (1974), pp. 294298.Google Scholar
[14] Fleissner, W., When is Jones' space normal?, Proceedings of the American Mathematical Society, vol. 50 (1975), pp. 375378.Google Scholar
[15] Fleissner, W., The normal Moore conjecture and large cardinals, Handbook of set-theoretic topology, North-Holland, 1984, pp. 733760.Google Scholar
[16] Fuchs, L., Infinite abelian groups, vol. I and II, Academic Press, 1970 and 1973.Google Scholar
[17] Hall, M., Distinct representatives of subsets, Bulletin of the American Mathematical Society, vol. 54 (1948), pp. 922926.Google Scholar
[18] Hall, P., On representatives of subsets, Journal of the London Mathematical Society, vol. 10 (1935), pp. 2630.CrossRefGoogle Scholar
[19] Hill, P., On the freeness of abelian groups: a generalization of Pontryagin's theorem, Bulletin of the American Mathematical Society, vol. 76 (1970), pp. 11181120.Google Scholar
[20] Hill, P., A special criterion for freeness, Symposia Mathematica, vol. 13 (1974), pp. 311314.Google Scholar
[21] Hodges, W., In singular cardinality, locally free algebras are free, Algebra Universalis, vol. 12(1981), pp. 205220.CrossRefGoogle Scholar
[22] Jech, T., Multiple forcing, Cambridge University Press, 1986.Google Scholar
[23] Jensen, R. B., Souslin's hypothesis is incompatible with V = L, Notices of the American Mathematical Society, vol. 15 (1968), p. 935.Google Scholar
[24] Jones, F. B., Concerning normal and completely normal spaces, Bulletin of the American Mathematical Society, vol. 43 (1937), pp. 671677.Google Scholar
[25] Jones, F. B., Remarks on the normal Moore space metrization problem, Proceedings of the 1965 wisconsin summer topology seminar, Annals of Math Studies, no. 60, Princeton, 1966.Google Scholar
[26] Kunen, K., Set theory: An introduction to independence proofs, North-Holland, 1980.Google Scholar
[27] Magidor, M. and Shelah, S., When does almost free imply free? (for groups, transversals, etc.), Journal of the American Mathematical Society, vol. 7 (1994), pp. 769830.Google Scholar
[28] Magnus, W., Karass, A., and Solitar, D., Combinatorial group theory, second revised ed., Dover, , 1976.Google Scholar
[29] Mekler, A. H., On Shelah's Whitehead groups and CH, Rocky Mountain Journal of Mathematics, vol. 12 (1982), pp. 271278.Google Scholar
[30] Mekler, A. H. and Shelah, S., Diamond and λ-title systems, Fundamenta Mathematica, vol. 131 (1988), pp. 4551.CrossRefGoogle Scholar
[31] Mekler, A. H. and Shelah, S., The consistency strength of “every stationary set reflects”, Israel Journal of Mathematics, vol. 67 (1989), pp. 353366.Google Scholar
[32] Mekler, A. H. and Shelah, S., Uniformization principles, this Journal, vol. 54 (1989), pp. 441459.Google Scholar
[33] Mekler, A. H. and Shelah, S., Almost free algebras, Israel Journal of Mathematics, vol. 89 (1995), pp. 237259.CrossRefGoogle Scholar
[34] Milner, E. C., Transversal theory, Proceedings of the International Congress of Mathematicians, vancouver, b. c., vol. 1, 1974, pp. 155169.Google Scholar
[35] Shelah, S., Infinite abelian groups, Whitehead problem and some constructions, Israel Journal of Mathematics, vol. 18 (1974), pp. 243256.Google Scholar
[36] Shelah, S., A compactness theorem for singular cardinals, free algebras, Whitehead problem and transversals, Israel Journal of Mathematics, vol. 21 (1975), pp. 319349.Google Scholar
[37] Shelah, S., Whitehead groups may not be free even assuming CH, I, Israel Journal of Mathematics, vol. 28 (1977), pp. 193203.Google Scholar
[38] Shelah, S., On uncountable abelian groups, Israel Journal of Mathematics, vol. 32 (1979), pp. 311330.CrossRefGoogle Scholar
[39] Shelah, S., Whitehead groups may not be free even assuming CH, II, Israel Journal of Mathematics, vol. 35 (1980), pp. 257285.Google Scholar
[40] Shelah, S., The consistency of Ext(G, ℤ) = ℚ, Israel Journal of Mathematics, vol. 39 (1981), pp. 7482.Google Scholar
[41] Shelah, S., Proper forcing, Lecture Notes in Mathematics, no. 940, Springer-Verlag, Berlin, 1982.Google Scholar
[42] Shelah, S., Incompactness in regular cardinals, Notre Dame Journal of Formal Logic, vol. 26 (1985), pp. 195228.Google Scholar
[43] Stein, K., Analytische Funktionen mehrerer komplexer Veränderlichen zu vorgegebenen Periodizitätsmoduln und das zweite Cousinsche Problem, Mathematische Annalen, vol. 123 (1951), pp. 201222.Google Scholar
[44] Tall, F., Normality versus collectionwise normality, Handbook of set-theoretic topology, North-Holland, 1984, pp. 685732.Google Scholar