Abstract
We introduce a vector-valued version of a uniform algebra, called the vector-valued function space over a uniform algebra. The diameter two properties of the vector-valued function space over a uniform algebra on an infinite compact Hausdorff space are investigated. Every nonempty relatively weakly open subset of the unit ball of a vector-valued function space \(A(K, (X, \tau ))\) over an infinite dimensional uniform algebra has diameter two, where \(\tau \) is a locally convex Hausdorff topology on a Banach space X compatible to a dual pair. Under the assumption of X equipped with the norm topology being uniformly convex and the additional condition that \(A\otimes X\subset A(K, X)\), it is shown that Daugavet points and \(\Delta \)-points on A(K, X) over a uniform algebra A are the same, and they are characterized by the norm-attainment at a limit point of the Shilov boundary of A. In addition, a sufficient condition for the convex diametral local diameter two property of A(K, X) is also provided. Similar results also hold for an infinite dimensional uniform algebra.
Similar content being viewed by others
References
Abrahamsen, T., Haller, R., Lima, V., Pirk, K.: Delta- and Daugavet points in Banach spaces. Proc. Edinb. Math. Soc. 63(2), 475–496 (2020)
Abrahamsen, T., Lima, V., Nygaard, O.: Remarks on diameter \(2\) properties. J. Convex Anal. 20(2), 439–452 (2013)
Abrahamsen, T., Nygaard, O., Põldvere, M.: New applications of extremely regular function spaces. Pac. J. Math. 301(2), 385–394 (2019)
Acosta, M.D., Kamińska, A.: Weak neighborhoods and the Daugavet property of the interpolation spaces \(L^1 + L^\infty \) and \(L^1\cap L^\infty \). Indiana Univ. Math. J. 57(1), 77–96 (2008)
Becerra Guerrero, J., López Pérez, G.: Relatively weakly open subsets of the unit ball in function spaces. J. Math. Anal. Appl. 315(2), 544–554 (2006)
Becerra Guerrero, J., López Pérez, G., Rueda Zoca, A.: Diametral diameter two properties in Banach spaces. J. Convex Anal. 25(3), 817–840 (2018)
Choi, Y.S., García, D., Kim, S.K., Maestre, M.: Some geometric properties of disk algebras. J. Math. Anal. Appl. 409(1), 147–157 (2014)
Cascales, B., Guirao, A., Kadets, V.: A Bishop–Phelps–Bollobás type theorem for uniform algebras. Adv. Math. 240, 370–382 (2013)
Dales, H.G.: Banach Algebras and Automatic Continuity. London Mathematical Society Monographs. New Series, vol. 24. The Clarendon Press, Oxford University Press, New York (2000)
Dantas, S., Martínez-Cervantes, G., Rodríguez Abellán, J.D., Rueda Zoca, A.: Octahedral norms in free Banach lattices. Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Mat. RACSAM 115(1) (2021). https://doi.org/10.1007/s13398-020-00940-1
Daugavet, I.K.: A property of completely continuous operators in the space \(C\). Uspekhi Mat. Nauk 18(5(113)), 157–158 (1963). (Russian)
Foia̧, C., Singer, I.: Points of Diffusion of Linear Operators and Almost Diffuse Operators in Spaces of Continuous Functions. Math. Z. 87, 434–450 (1965)
Ghoussoub, N., Godefroy, G., Maurey, B., Schachermayer, W.: Some topological and geometrical structures in Banach spaces. Mem. Am. Math. Soc. 70(378) (1987)
Haller, R., Langemets, J., Lima, V., Nadel, R.: Symmetric strong diameter two property. Mediterr. J. Math. 16(2), Art. 35 (2019)
Ivakhno, Y., Kadets, V.: Unconditional sums of spaces with bad projections. Visn. Khark. Univ. Ser. Mat. Pryki. Mat. Mekh. 645, 30–35 (2004)
Kadets, V.: The diametral strong diameter 2 property of Banach spaces is the same as the Daugavet property. Proc. Am. Math. Soc. 149, 2579–2582 (2021)
Kim, S.K., Lee, H.J.: A Urysohn-type theorem and the Bishop–Phelps–Bollobás theorem for holomorphic functions. J. Math. Anal. Appl. 480(2), Art. 123393 (2019)
Langemets, J., Lima, V., Rueda Zoca, A.: Almost square and octahedral norms in tensor products of Banach spaces. Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Mat. RACSAM 111(3), 841–853 (2017)
Langemets, J., Pirk, K.: Stability of diametral diameter two properties. Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Mat. RACSAM 115(2) (2021). https://doi.org/10.1007/s13398-021-01038-y
Lee, H.J.: Generalized numerical index of function algebras. J. Funct. Spaces 2019 (2019). https://doi.org/10.1155/2019/9080867
Leibowitz, G.M.: Lectures on Complex Function Algebras. Scott, Foresman and Company, Northbrook (1970)
López-Pérez, G., Rueda Zoca, A.: Diameter two properties and polyhedrality. Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Mat. RACSAM 113, 131–135 (2019)
Lozanovskii, G.. Ya..: On almost integral operators in KB-spaces. Vestnik Leningr. Univ. Mat. Mekh. Astr. 21, 35–44 (1966). (Russian)
Narici, L., Beckenstein, E.: Topological Vector Spaces. Pure and Applied Mathematics, 2nd edn. CRC Press, New York (2011)
Nygaard, O., Werner, D.: Slices in the unit ball of a uniform algebra. Arch. Math. (Basel) 76(6), 441–444 (2001)
Ostrak, A.: On the duality of the symmetric strong diameter two property in Lipschitz spaces. Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Mat. RACSAM 115(2) (2021). https://doi.org/10.1007/s13398-021-01018-2
Pirk, K.: Diametral diameter two properties, Daugavet-, and \(\Delta \)-points in Banach spaces. PhD dissertation. Dissertationes Mathematicae Universitatis Tartuensis, 133 (2020)
Rudin, W.: Functional Analysis, 2nd edn. McGraw-Hill Inc., New York (1991)
Rueda Zoca, A.: Almost squareness and strong diameter two property in tensor product spaces. Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Mat. RACSAM 114(2) (2021). https://doi.org/10.1007/s13398-020-00816-4
Schaefer, H., Wolff, M.: Topological Vector Spaces. Graduate Texts in Mathematics, vol. 3, 2nd edn. Springer, New York (1999)
Werner, D.: Recent progress on the Daugavet property. Ir. Math. Soc. Bull. 46, 77–97 (2001)
Werner, D.: The Daugavet equation for operators not fixing a copy of \(C[0,1]\). J. Oper. Theory 39, 89–98 (1998)
Wojtaszczyk, P.: Some remarks on the Daugavet equation. Proc. Am. Math. Soc. 115, 1047–1052 (1992)
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
H. J. Lee was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2020R1A2C1A01010377). H.-J. Tag was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2020R1A2C1A01010377, NRF-2020R1C1C1A01010133)
Rights and permissions
About this article
Cite this article
Lee, H.J., Tag, HJ. Diameter two properties in some vector-valued function spaces. RACSAM 116, 17 (2022). https://doi.org/10.1007/s13398-021-01165-6
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s13398-021-01165-6