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Mackey continuity of convex functions on dual Banach spaces: a review. (English) Zbl 1469.46075

Summary: A convex (or concave) real-valued function, \(f\), on a dual Banach space \(P^\ast\) is continuous for the Mackey topology m\((P^\ast,P)\) if (and only if) it is Mackey continuous on bounded subsets of \(P^\ast\). Equivalence of Mackey continuity to sequential Mackey continuity follows when \(P\) is strongly weakly compactly generated, e.g., when \(P=L^1(T)\), where \(T\) is a set that carries a sigma-finite measure \(\sigma\). This result of Delbaen, Orihuela and Owari [F. Delbaen and K. Owari, Positivity 23, No. 5, 1051–1064 (2019; Zbl 1439.46023); F. Delbaen and J. Orihuela, J. Math. Anal. Appl. 485, No. 1, Article ID 123764, 15 p. (2020; Zbl 1433.91051)] extends their earlier work on the case that \(P^\ast\) is either \(L^\infty(T)\) or a dual Orlicz space. An earlier result of this kind is recalled also: it derives Mackey continuity from bounded Mackey continuity for a nondecreasing concave function, \(F\), that is defined and finite only on the nonnegative cone \(L^\infty_+\). Applied to a linear \(f\), the Delbaen-Orihuela-Owari result shows that the convex bounded Mackey topology is identical to the Mackey topology, i.e., cbm\((P^\ast,P)=\mathrm{m }(P^\ast,P)\); here, this is shown to follow also from Grothendieck’s Completeness Theorem. As for the bounded Mackey topology, bm\((P^\ast,P)\), it is conjectured here not to be a vector topology, or equivalently to be strictly stronger than m\((P^\ast,P)\), except when \(P\) is reflexive.

MSC:

46N10 Applications of functional analysis in optimization, convex analysis, mathematical programming, economics
46A20 Duality theory for topological vector spaces
46E30 Spaces of measurable functions (\(L^p\)-spaces, Orlicz spaces, Köthe function spaces, Lorentz spaces, rearrangement invariant spaces, ideal spaces, etc.)
52A41 Convex functions and convex programs in convex geometry
46A70 Saks spaces and their duals (strict topologies, mixed topologies, two-norm spaces, co-Saks spaces, etc.)

References:

[1] C.D. Aliprantis, K.C. Border,“ Infinite Dimensional Analysis ”, Springer, Berlin-Heidelberg-New York, 2006. doi.org/10.1007/3-540-29587-9 · Zbl 1156.46001
[2] C.D. Aliprantis, O. Burkinshaw,“ Locally Solid Riesz Spaces with Applications to Economics ”, American Mathematical Society, Providence, RI, 2003. doi.org/10.1090/surv/105 · Zbl 1043.46003
[3] T.F. Bewley,Existence of equilibria in economies with infinitely many commodities,J. Econom. Theory4(3) (1972), 514 - 540. doi.org/10.1016/0022-0531(72)90136-6
[4] H.S. Collins,Completeness and compactness in linear topological spaces, Trans. Amer. Math. Soc.79(1955), 256 - 280. doi.org/10.1090/S0002-9947-1955-0069386-1 · Zbl 0064.35502
[5] J.B. Cooper,“ Saks Spaces and Applications to Functional Analysis ”, Second edition, North-Holland, Amsterdam, 1987. doi.org/10.1016/S0304-0208(08)72315-6 · Zbl 0618.46003
[6] F. Delbaen, J. Orihuela,Mackey constraints for James’s compactness theorem and risk measures,J. Math. Anal. Appl.485(1) (2020), Article 123764. doi.org/10.1016/j.jmaa.2019.123764 · Zbl 1433.91051
[7] F. Delbaen, K. Owari,Convex functions on dual Orlicz spaces,Positivity 23(5) (2019), 1051 - 1064. doi.org/10.1007/s11117-019-00651-x · Zbl 1439.46023
[8] J. Gil de Lamadrid,Topology of mappings and differentiation processes, Illinois J. Math.3(1959), 408 - 420. doi.org/10.1215/ijm/1255455262 · Zbl 0116.32803
[9] J. G´omez Gil,On local convexity of bounded weak topologies on Banach spaces,Pacific J. Math.110(1) (1984), 71 - 76. doi.org/10.2140/pjm.1984.110.71 · Zbl 0553.46011
[10] M. Gonz´alez, J.M. Guti´errez,The compact weak topology on a Banach space,Proc. Roy. Soc. Edinburgh Sect. A120(3-4) (1992), 367 - 379. doi.org/10.1017/s0308210500032194 · Zbl 0786.46018
[11] A. Horsley, A.J. Wrobel,Efficiency rents of storage plants in peak-load pricing, II: hydroelectricity, LSE, 1999, STICERD DP TE/99/372.http: //sticerd.lse.ac.uk/dps/te/te372.pdfShortened journal version is at doi.org/10.1016/j.jedc.2006.03.004
[12] A. Horsley, A.J. Wrobel,Localisation of continuity to bounded sets for nonmetrisable vector topologies and its applications to economic equilibrium theory,Indag. Math. (New Ser.)11(1) (2000), 53 - 61. doi.org/10.1016/S0019-3577(00)88573-0 · Zbl 0987.46049
[13] A. Horsley, A.J. Wrobel,Boiteux’s solution to the shifting-peak problem and the equilibrium price density in continuous time,Econom. Theory20(3) (2002), 503 - 537. doi.org/10.1007/s001990100226 · Zbl 1031.91029
[14] A. Horsley, A.J. Wrobel,Demand continuity and equilibrium in Banach commodity spaces, in “Game Theory and Mathematical Economics”, Banach Center Publications, 71, Polish Acad. Sci. Inst. Math., Warsaw, 2006, 163 - 183. doi.org/10.4064/bc71-0-13 · Zbl 1255.91230
[15] A. Horsley, A.J. Wrobel,“The Short-Run Approach to Long-Run Equilibrium in Competitive Markets: A General Theory with Application to Peak-Load Pricing with Storage”, Lect. Notes Econ. Math. Sys. 684, Springer, Berlin-Heidelberg-New York, 2016. doi.org/10.1007/978-3-319-33398-4 · Zbl 1357.91002
[16] M. Nowak,On the finest Lebesgue topology on the space of essentially bounded measurable functions,Pac. J. Math.140(1) (1989), 151 - 161. doi.org/10.2140/pjm.1989.140.155 · Zbl 0696.46028
[17] H.H. Schaefer,“ Topological Vector Spaces ”, Second edition, SpringerVerlag, New York, 1999. doi.org/10.1007/978-1-4612-1468-7 · Zbl 0983.46002
[18] G. Schl¨uchtermann, R.F. Wheeler,On strongly WCG Banach spaces, Math. Z.199(3) (1988), 387 - 398. doi.org/10.1007/bf01159786 · Zbl 0637.46011
[19] A. Wiweger,Linear spaces with mixed topology,Studia Math.20(1961), 47 - 68. doi.org/10.4064/sm-20-1-47-68 · Zbl 0097.31301
[20] A.
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