Previous |  Up |  Next

Article

Full entry | Fulltext not available (moving wall 24 months)      Feedback
Keywords:
free locally convex space; $L$-equivalence; retraction
Summary:
We study the relation of $L$-equivalence defined between Tychonoff spaces, that is, we study the topological isomorphisms of their respective free locally convex spaces. We introduce the concept of an $L$-retract in a Tychonoff space in terms of the existence of a special kind of simultaneous extensions of continuous functions, explore the relation of this concept with the Dugundji extension theorem, and find some conditions that allow us to identify $L$-retracts in various classes of topological spaces. As applications, we present a method for constructing examples of $L$-equivalent mappings and $L$-equivalent spaces and in particular, we show that the properties of being an open mapping or a perfect mapping are not $L$-invariant.
References:
[1] Arhangel'skii A. V.: Linear homomorphisms of function spaces. Dokl. Akad. Nauk SSSR 264 (1982), no. 6, 1289–1292 (Russian). MR 0664477
[2] Arhangel'skiĭ A. V.: Topological Function Spaces. Math. Appl. (Soviet Ser.), 78, Kluwer Academic Publishers Group, Dordrecht, 1992.
[3] Arhangel'skii A. V.: Paracompactness and Metrization. The Method of Covers in the Classification of Spaces. General Topology, III, Encyclopaedia Math. Sci., 51, Springer, Berlin, 1995. DOI 10.1007/978-3-662-07413-8_1
[4] Cauty R.: Un espace métrique linéaire qui n'est pas un rétracte absolu. Fund. Math. 146 (1994), no. 1, 85–99 (French. English summary). DOI 10.4064/fm-146-1-85-99 | MR 1305261
[5] Collins P. J., Roscoe A. W.: Criteria for metrizability. Proc. Amer. Math. Soc. 90 (1984), no. 4, 631–640. DOI 10.1090/S0002-9939-1984-0733418-9 | MR 0733418
[6] Engelking R.: General Topology. Sigma Ser. Pure Math., 6, Heldermann Verlag, Berlin, 1989. MR 1039321 | Zbl 0684.54001
[7] Flood J.: Free Topological Vector Spaces. Dissertationes Math. (Rozprawy Mat.) 221 (1984), 95 pages. MR 0741750
[8] Gabriyelyan S. S., Morris S. A.: Free topological vector spaces. Topology Appl. 223 (2017), 30–49. DOI 10.1016/j.topol.2017.03.006 | MR 3633732
[9] Hoshina T., Yamazaki K.: Weak $C$-embedding and $P$-embedding, and product spaces. Topology Appl. 125 (2002), no. 2, 233–247. DOI 10.1016/S0166-8641(01)00275-9 | MR 1933574
[10] Karnik S. M., Willard S.: Natural covers and $R$-quotient maps. Canad. Math. Bull. 25 (1982), no. 4, 456–461. DOI 10.4153/CMB-1982-065-1 | MR 0674562
[11] Michael E.: Some extension theorems for continuous functions. Pacific J. Math. 3 (1953), 789–806. DOI 10.2140/pjm.1953.3.789 | MR 0059541
[12] Okunev O. G.: A method for constructing examples of $M$-equivalent spaces. Seminar on General Topology and Topological Algebra, Moscow, 1988/1989, Topology Appl. 36 (1990), no. 2, 157–171. DOI 10.1016/0166-8641(90)90006-N | MR 1068167
[13] Okunev O. G.: $M$-equivalence of products. Trudy Moskov. Mat. Obshch. 56 (1995), 192–205, 351 (Russian); translation in Trans. Moscow Math. Soc. (1995), 149–158. MR 1468468
[14] Schaefer H. H.: Topological Vector Spaces. Graduate Texts in Mathematics, 3, Springer, New York, 1971. MR 0342978 | Zbl 0983.46002
[15] Sennott L. I.: A necessary condition for a Dugundji extension property. Proc. of the 1984 Topology Conf., Auburn, Ala., 1984, Topology Proc. 2 (1977), no. 1, 265–280. MR 0540611
[16] Uspenskiĭ V. V.: On the topology of a free locally convex space. Dokl. Akad. Nauk SSSR 270 (1983), no. 6, 1334–1337 (Russian). MR 0712944
[17] Yamazaki K.: Extending pointwise bounded equicontinuous collections of functions. Tsukuba J. Math. 29 (2005), no. 1, 197–213. DOI 10.21099/tkbjm/1496164899 | MR 2162836
Partner of
EuDML logo