We express the fundamental properties of commutative polygroups (also known as canonical hypergroups) in category-theoretic terms, over the category $ \mathbf{Set} $ formed by sets and functions. For this, we employ regularity as well as the monoidal structure induced on the category $ {\mathbf{Rel}} $ of sets and relations by cartesian products. We highlight how our approach can be generalised to any regular category. In addition, we consider the theory of partial multirings and find fully faithful functors between certain slice or coslice categories of the category of partial multirings and other categories formed by well-known mathematical structures and their morphisms.
Citation: Alessandro Linzi. Polygroup objects in regular categories[J]. AIMS Mathematics, 2024, 9(5): 11247-11277. doi: 10.3934/math.2024552
We express the fundamental properties of commutative polygroups (also known as canonical hypergroups) in category-theoretic terms, over the category $ \mathbf{Set} $ formed by sets and functions. For this, we employ regularity as well as the monoidal structure induced on the category $ {\mathbf{Rel}} $ of sets and relations by cartesian products. We highlight how our approach can be generalised to any regular category. In addition, we consider the theory of partial multirings and find fully faithful functors between certain slice or coslice categories of the category of partial multirings and other categories formed by well-known mathematical structures and their morphisms.
[1] | M. Anderson, T. Feil, Lattice-ordered groups, Springer Dordrecht, 1988. https://doi.org/10.1007/978-94-009-2871-8 |
[2] | S. Awodey, Category theory, Oxford: Oxford University Press, 2010. |
[3] | M. Baker, N. Bowler, Matroids over partial hyperstructures, Adv. Math., 343 (2019), 821–863. https://doi.org/10.1016/j.aim.2018.12.004 doi: 10.1016/j.aim.2018.12.004 |
[4] | M. Baker, O. Lorscheid, Descartes' rule of signs, Newton polygons, and polynomials over hyperfields, J. Algebra, 569 (2021), 416–441. https://doi.org/10.1016/j.jalgebra.2020.10.024 doi: 10.1016/j.jalgebra.2020.10.024 |
[5] | W. Borczyk, P. Gładki, K. Worytkiewicz, A survey of selected categorical properties of algebras with multivalued addition, Banach Center Publications, 121 (2020), 9–24 https://doi.org/10.4064/bc121-1. doi: 10.4064/bc121-1 |
[6] | N. Bowler, T. Su, Classification of doubly distributive skew hyperfields and stringent hypergroups, J. Algebra, 574 (2021), 669–698. https://doi.org/10.1016/j.jalgebra.2021.01.031 doi: 10.1016/j.jalgebra.2021.01.031 |
[7] | S. D. Comer, Combinatorial aspects of relations, Algebr. Univ., 18 (1984), 77–94. https://doi.org/10.1007/BF01182249 doi: 10.1007/BF01182249 |
[8] | A. Connes, C. Consani, From monoids to hyperstructures: In search of an absolute arithmetic, In: Casimir force, Casimir operators and the Riemann hypothesis, Berlin: de Gruyter, 2010,147–198. |
[9] | A. Connes, C. Consani, The hyperring of adèle classes, J. Number Theory, 131 (2011), 159–194. https://doi.org/10.1016/j.jnt.2010.09.001 doi: 10.1016/j.jnt.2010.09.001 |
[10] | K. M. de Andrade Roberto, H. L. Mariano, On superrings of polynomials and algebraically closed multifields, 2021, arXiv: 2111.12195. |
[11] | R. Diaconescu, Institution-independent model theory, Basel: Birkhäuser Verlag, 2008. |
[12] | M. Dresher, O. Ore, Theory of multigroups, Amer. J. Math., 60 (1938), 705–733. |
[13] | A. J. Dudzik, Quantales and hyperstructures, In: UC Berkeley electronic theses and dissertations, 2016. Available from: https://escholarship.org/uc/item/1zg7f5pp |
[14] | C. Eppolito, J. Jun, M. Szczesny, Hopf algebras for matroids over hyperfields, J. Algebra, 556 (2020), 806–835. https://doi.org/10.1016/j.jalgebra.2020.02.042 doi: 10.1016/j.jalgebra.2020.02.042 |
[15] | J. Flenner, Relative decidability and definability in {H}enselian valued fields, J. Symb, Logic, 76 (2011), 1240–1260. https://doi.org/10.2178/jsl/1318338847 doi: 10.2178/jsl/1318338847 |
[16] | P. Gładki, Orderings of higher level in multifields and multirings, Ann. Math. Silesianae, 24 (2010), 15–25. |
[17] | R. Goldblatt, Topoi: The categorial analysis of logic, 1984. |
[18] | J. Jantosciak, Transposition hypergroups: noncommutative join spaces, J. Algebra, 187 (1997), 97–119, https://doi.org/10.1006/jabr.1997.6789. doi: 10.1006/jabr.1997.6789 |
[19] | S. Jančić-Rašović, I. Cristea, Hypernear-rings with a defect of distributivity, Filomat, 32 (2018), 1133–1149. https://doi.org/10.2298/FIL1804133J doi: 10.2298/FIL1804133J |
[20] | P. Jell, C. Scheiderer, J. Yu, Real tropicalization and analytification of semialgebraic sets, Int. Math. Res. Notices, 2022 (2022), 928–958. https://doi.org/10.1093/imrn/rnaa112 doi: 10.1093/imrn/rnaa112 |
[21] | A. Jenčová, G. Jenča, On monoids in the category of sets and relations, Int. J. Theor. Phys., 56 (2017), 3757–3769. https://doi.org/10.1007/s10773-017-3304-z doi: 10.1007/s10773-017-3304-z |
[22] | P. T. Johnstone, Sketches of an elephant: A topos theory compendium, New York: Oxford University Press, 2002. https://doi.org/10.1093/oso/9780198515982.001.0001 |
[23] | J. Jun, Algebraic geometry over hyperrings, Adv. Math., 323 (2018), 142–192. https://doi.org/10.1016/j.aim.2017.10.043 doi: 10.1016/j.aim.2017.10.043 |
[24] | J. Jun, Geometry of hyperfields, J. Algebra, 569 (2021), 220–257. https://doi.org/10.1016/j.jalgebra.2020.11.005 doi: 10.1016/j.jalgebra.2020.11.005 |
[25] | M. Krasner, Approximation des corps valués complets de caractéristique $p\not = 0$ par ceux de caractéristique $0$, Centre Belge de Recherches Mathématiques, 1957,129–206. Available from: https://mathscinet.ams.org/mathscinet-getitem?mr = 106218 |
[26] | K. Kuhlmann, A. Linzi, H. Stojałowska, Orderings and valuations in hyperfields, J. Algebra, 611 (2022), 399–421. https://doi.org/10.1016/j.jalgebra.2022.08.006 doi: 10.1016/j.jalgebra.2022.08.006 |
[27] | T. Leinster, Basic category theory, Cambridge: Cambridge University Press, 2014. https://doi.org/10.1017/CBO9781107360068 |
[28] | A. Linzi, A result of Krasner in categorial form, Mathematics, 11 (2023), 4923. https://doi.org/10.3390/math11244923 doi: 10.3390/math11244923 |
[29] | A. Linzi, Algebraic hyperstructures in the model theory of valued fields, Ph. D thesis, University of Szczecin (Uniwersytet Szczeciński), Poland, 2022. Available form: https://bip.usz.edu.pl/doktorat-habilitacja/16282/alessandro-linzi |
[30] | A. Linzi, Notes on valuation theory for Krasner hyperfields, 2023, arXiv: 2301.08639. |
[31] | S. M. Lane, Categories for the working mathematician, New York: Springer, 1971. https://doi.org/10.1007/978-1-4612-9839-7 |
[32] | M. Marshall, Real reduced multirings and multifields, J. Pure Appl. Algebra, 205 (2006), 452–468, https://doi.org/10.1016/j.jpaa.2005.07.011. doi: 10.1016/j.jpaa.2005.07.011 |
[33] | F. Marty, Sur une généralization de la notion de groupe, 1934, 45–49. |
[34] | F. Marty, Rôle de la notion de hypergroupe dans l'étude de groupes non abéliens, C. R. Acad. Sci. (Paris), 201 (1935), 636–638. |
[35] | F. Marty, Sur les groupes et hypergroupes attaches à une fraction rationnelle, Ann. Sci. École Norm. Sup., 53 (1936), 83–123. https://doi.org/10.24033/asens.854 doi: 10.24033/asens.854 |
[36] | C. Massouros, G. Massouros, An overview of the foundations of the hypergroup theory, Mathematics, 9 (2010), 1014. https://www.mdpi.com/2227-7390/9/9/1014 |
[37] | J. Maxwell, B. Smith, Convex geometry over ordered hyperfields, 2023, arXiv: 2301.12760. |
[38] | J. Mittas, Hypergroupes canoniques, Math. Balkanica, 2 (1972), 165–179. https://mathscinet.ams.org/mathscinet-getitem?mr = 319864 |
[39] | S. Nakamura, M. L. Reyes, Categories of hypermagmas, hypergroups, and related hyperstructures, 2023, arXiv: 2304.09273. |
[40] | T. Nakano, Rings and partly ordered systems, Math. Z., 99 (1967), 355–376. https://doi.org/10.1007/BF01111015 doi: 10.1007/BF01111015 |
[41] | G. Nordo, An algorithm on number of isomorphism classes of hypergroups of order $3$, Ital. J. Pure Appl. Math., 1997, 37–42. |
[42] | W. Prenowitz, J. Jantosciak, Join geometries: A theory of convex sets and linear geometry, Undergraduate Texts in Mathematics, New York-Heidelberg: Springer-Verlag, 1979. Available from: https://mathscinet.ams.org/mathscinet-getitem?mr = 528635 |
[43] | L. H. Rowen, Algebras with a negation map, Eur. J. Math., 8 (2022), 62–138. https://doi.org/10.1007/s40879-021-00499-0 doi: 10.1007/s40879-021-00499-0 |
[44] | K. Thas, The Connes-Consani plane connection, J. Number Theory, 167 (2016), 407–429, https://doi.org/10.1016/j.jnt.2016.03.007 doi: 10.1016/j.jnt.2016.03.007 |
[45] | P. Touchard, Transfer principles in {H}enselian valued fields, Bull. Symb. Logic., 27 (2021), 222–223. https://doi.org/10.1017/bsl.2021.31 doi: 10.1017/bsl.2021.31 |
[46] | O. Viro, Hyperfields for tropical geometry I. hyperfields and dequantization, 2010, arXiv: 1006.3034. |