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Bounded strict solar property of strict suns in the space C(Q)

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Abstract

The intersection of an arbitrary strict sun M in C(Q) with a closed span Π ⊂ C(Q) (in particular, with a closed ball) is shown to be a strict protosun, provided that the natural condition M ∩ int Π ≠ Ø is satisfied. This property is shown to characterize closed spans in C(Q).

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References

  1. L. P. Vlasov, “Approximative Properties of Sets in Normed Linear Spaces,” Uspekhi Matem. Nauk 28(6), 3 (1973) [Russ. Math. Surv. 28 (6), 1 (1973)].

    MathSciNet  MATH  Google Scholar 

  2. B. Brosowski and R. Wegmann, “Charakterisierung bester Approximationen in normierten Vektorraumen,” J. Ap-prox. Theory, 3(4), 369 (1970).

    Article  MathSciNet  MATH  Google Scholar 

  3. W. Yang, Ch. Li, and G. A. Watson, “Characterization and Uniqueness of Nonlinear Uniform Approximation,” Proc. Edinburgh Math. Soc. 40, 473 (1997).

    Article  MathSciNet  Google Scholar 

  4. V. A. Koshcheev, “Connectedness and Solar Properties of Sets in Normed Linear Spaces,” Matem. Zametki 19(2), 267 (1976) [Math. Notes 19 (2), 158 (1976)].

    Google Scholar 

  5. A. P. Alimov, “Connectedness of Suns in the Space c 0,” Izvestiya Rus. Akad. Nauk, Ser. Matem. 69(4), 3 (2005) [Izvestiya: Math. 69 (4), 651 (2005)].

    MathSciNet  Google Scholar 

  6. A. P. Alimov, “Preservation of Approximative Properties of Subsets of Chebyshev Sets and Suns in ℓ(n),” Izvestiya Rus. Akad. Nauk, Ser. Matem. 70(5), 3 (2006) [Izvestiya: Math. 70 (5), 857 (2006)].

    MathSciNet  Google Scholar 

  7. A. P. Alimov, “Monotone Path-Connectedness of Chebyshev Sets in the Space C(Q),” Matem. Sborn. 197(9), 3 (2006) [Sbornik: Math. 197 (9), 1259 (2006)].

    Article  MathSciNet  Google Scholar 

  8. A. P. Alimov, “Preservation of Approximative Properties of Subsets of Chebyshev Sets in a Plane,” Vestnik Mosk. Univ., Matem. Mekhan., No. 4, 46 (2008) [Moscow Univ. Math. Bulletin 63 (5), 198 (2008)].

    Google Scholar 

  9. A. A. Vasil’eva, “Closed Spans in Vector-Valued Function Spaces and their Approximative Properties,” Izvestiya Rus. Akad. Nauk, Ser. Matem. 68(4), 75 (2004) [Izvestiya: Math. 68 (4), 709 (2004)].

    MathSciNet  Google Scholar 

  10. A. P. Alimov, “Geometrical Characterization of Strict Suns in ℓ(n),” Matem. Zametki 70(1), 3 (2001) [Math. Notes 70 (1), 3 (2001)].

    MathSciNet  MATH  Google Scholar 

  11. A. R. Alimov, “Characterizations of Chebyshev sets in c 0,” J. Approx. Theory 129, 217 (2004).

    Article  MathSciNet  MATH  Google Scholar 

  12. A. R. Alimov and V. Yu. Protasov, “Separability of Convex Sets by Extreme Hyperplanes,” Fundam. Prikl. Matem. 17(4), 3 (2012).

    MathSciNet  Google Scholar 

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Original Russian Text © A.P. Alimov, 2012, published in Vestnik Moskovskogo Universiteta, Matematika. Mekhanika, 2012, Vol. 67, No. 6, pp. 16–19.

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Alimov, A.P. Bounded strict solar property of strict suns in the space C(Q) . Moscow Univ. Math. Bull. 68, 14–17 (2013). https://doi.org/10.3103/S0027132213010038

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  • DOI: https://doi.org/10.3103/S0027132213010038

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