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Lagrange's Theorem for Hopf Monoids in Species

Published online by Cambridge University Press:  20 November 2018

Marcelo Aguiar
Affiliation:
Department of Mathematics, Texas A&M University, College Station, TX, 77843, USA, e-mail: maguiar@math.tamu.edu
Aaron Lauve
Affiliation:
Department of Mathematics and Statistics, Loyola University Chicago, Chicago, IL, 60660, USA, e-mail: lauve@math.luc.edu
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Abstract

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Following Radford's proof of Lagrange's theorem for pointed Hopf algebras, we prove Lagrange‘s theorem for Hopf monoids in the category of connected species. As a corollary, we obtain necessary conditions for a given subspecies $\mathbf{k}$ of a Hopf monoid $\mathbf{h}$ to be a Hopf submonoid: the quotient of any one of the generating series of $\mathbf{h}$ by the corresponding generating series of $\mathbf{k}$ must have nonnegative coefficients. Other corollaries include a necessary condition for a sequence of nonnegative integers to be the dimension sequence of a Hopf monoid in the form of certain polynomial inequalities and of a set-theoretic Hopf monoid in the form of certain linear inequalities. The latter express that the binomial transform of the sequence must be nonnegative.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 2013

References

[1] Abe, E., Hopf algebras. Translated from the Japanese by Hisae Kinoshita and Hiroko Tanaka, Cambridge Tracts in Mathematics, 74, Cambridge University Press, Cambridge-New York, 1980.Google Scholar
[2] Aguiar, M. and Mahajan, S., Monoidal functors, species and Hopf algebras. CRM Monograph Series, 29, American Mathematical Society, Providence, RI, 2010.Google Scholar
[3] Aguiar, M. and Sottile, F., Cocommutative Hopf algebras of permutations and trees. J. Algebraic Combin. 22(2005), 451470. http://dx.doi.org/10.1007/s10801-005-4628-y Google Scholar
[4] Bergeron, F., Labelle, G., and Leroux, P., Combinatorial species and tree-like structures. Translated from the 1994 French original by Margaret Readdy, with a foreword by Gian-Carlo Rota, Encyclopedia of Mathematics and its Applications, 67, Cambridge University Press, Cambridge, 1998.Google Scholar
[5] Blattner, R. J., Cohen, M., and Montgomery, S., Crossed products and inner actions of Hopf algebras. Trans. Amer. Math. Soc. 298(1986), 671711. http://dx.doi.org/10.1090/S0002-9947-1986-0860387-X Google Scholar
[6] Dekker, J. C. E., Myhill's theory of combinatorial functions. Modern Logic 1(1990), no. 1, 321.Google Scholar
[7] Garsia, A. M. and Wallach, N., Qsym over Sym is free. J. Combin. Theory Ser. A 104(2003), no. 2, 217263. http://dx.doi.org/10.1016/S0097-3165(03)00042-6 Google Scholar
[8] Jacobson, N., Lie algebras. Republication of the 1962 original, Dover Publications Inc. , New York,1979.Google Scholar
[9] Joyal, A., Une théorie combinatoire des séries formelles. Adv. in Math. 42(1981), no. 1, 182. http://dx.doi.org/10.1016/0001-8708(81)90052-9 Google Scholar
[10] Kaplansky, I., Bialgebras. Lecture Notes in Mathematics, Department of Mathematics, University of Chicago, Chicago, Ill., 1975.Google Scholar
[11] Larson, R. G. and Sweedler, M. E., An associative orthogonal bilinear form for Hopf algebras. Amer. J. Math. 91(1969), 7594. http://dx.doi.org/10.2307/2373270 Google Scholar
[12] Lauve, A. and Mason, S. K., Qsym over sym has a stable basis. J. Combin. Theory Ser. A 118(2011), no. 5, 16611673. http://dx.doi.org/10.1016/j.jcta.2011.01.008 Google Scholar
[13] Lothaire, M.. Combinatorics on words.With a foreword by Roger Lyndon and a preface by Dominique Perrin. Corrected reprint of the 1983 original, with a new preface by Perrin, Cambridge Mathematical Library, Cambridge University Press, Cambridge, 1997.Google Scholar
[14] Lyubashenko, V., Modular transformations for tensor categories. J. Pure Appl. Algebra 98(1995), no. 3, 279327. http://dx.doi.org/10.1016/0022-4049(94)00045-K Google Scholar
[15] Macdonald., I. G. Symmetric functions and Hall polynomials Second ed., Oxford Mathematical Monographs, The Clarendon Press, Oxford University Press, New York, 1995.Google Scholar
[16] Masuoka, A., Freeness of Hopf algebras over coideal subalgebras. Comm. Algebra 20(1992), no. 5, 13531373. http://dx.doi.org/10.1080/00927879208824408 Google Scholar
[17] Menni, M.. Algebraic categories whose projectives are explicitly free. Theory Appl. Categ. 22(2009), no. 20, 509541.Google Scholar
[18] Montgomery, S., Hopf algebras and their actions on rings. CBMS Regional Conference Series in Mathematics, 82, Published for the Conference Board of the Mathematical Sciences,Washington, DC; by the American Mathematical Society, Providence, RI, 1993.Google Scholar
[19] Myhill, J., Recursive equivalence types and combinatorial functions. Bull. Amer. Math. Soc. 64(1958), 373376. http://dx.doi.org/10.1090/S0002-9904-1958-10241-4 Google Scholar
[20] Nichols, W. D. and Zoeller, M. B., A Hopf algebra freeness theorem. Amer. J. Math. 111(1989), no. 2, 381385. http://dx.doi.org/10.2307/2374514 Google Scholar
[21] Oberst, U. and Schneider, H.-J., Untergruppen formeller Gruppen von endlichem Index. J. Algebra 31(1974), 1044. http://dx.doi.org/10.1016/0021-8693(74)90003-9 Google Scholar
[22] Radford, D. E., Pointed Hopf algebras are free over Hopf subalgebras. J. Algebra 45(1977), no. 2, 266273. http://dx.doi.org/10.1016/0021-8693(77)90326-X Google Scholar
[23] Radford, D. E., A natural ring basis for the shuffle algebra and an application to group schemes. J. Algebra 58(1979), no. 2, 432454. http://dx.doi.org/10.1016/0021-8693(79)90171-6 Google Scholar
[24] Reutenauer, C., Free Lie algebras. London Mathematical Society Monographs. New Series, 7, Oxford Science Publications, The Clarendon Press, Oxford University Press, New York, 1993.Google Scholar
[25] Reutenauer, C., Free Lie algebras. In: Handbook of algebra, 3, North-Holland, Amsterdam, 2003, pp. 887903.Google Scholar
[26] Rosales, J. C. and Garcίa-Sánchez, P. A., Numerical semigroups. Developments in Mathematics, 20, Springer, New York, 2009.Google Scholar
[27] Schneider, H.-J., Principal homogeneous spaces for arbitrary Hopf algebras. Israel J. Math. 72(1990), no. 1–2, 167195. http://dx.doi.org/10.1007/BF02764619 Google Scholar
[28] Schneider, H.-J., Normal basis and transitivity of crossed products for Hopf algebras. J. Algebra 152(1992), no. 2, 289312. http://dx.doi.org/10.1016/0021-8693(92)90034-J Google Scholar
[29] Sloane, N. J. A., The on-line encyclopedia of integer sequences. http://www.research.att.com/_njas/sequences, OEIS.Google Scholar
[30] Sommerhäuser, Y., On Kaplansky's conjectures. In: Interactions between ring theory and representations of algebras (Murcia), Lecture Notes in Pure and Appl. Math., 210, Dekker, New York, 2000, pp. 393412.Google Scholar
[31] Stanley, R. P., Enumerative combinatorics. 2. Cambridge Studies in Advanced Mathematics, 62, Cambridge University Press, Cambridge, 1999.Google Scholar
[32] M. Takeuchi, , Relative Hopf modules—equivalences and freeness criteria. J. Algebra 60(1979), no. 2, 452471. http://dx.doi.org/10.1016/0021-8693(79)90093-0 Google Scholar
[33] M. Takeuchi, , Finite Hopf algebras in braided tensor categories. J. Pure Appl. Algebra 138, no. 1, 5982. http://dx.doi.org/10.1016/S0022-4049(97)00207-7 Google Scholar
[34] Wang, D. G., Zhang, J. J., and Zhuang, G.. Hopf algebras of GK-dimension two with vanishing Ext-group. arxiv:1105.0033v1 Google Scholar