Let γ be a regular curve. We study the local properties of singular integrals in the class of functions \({H}_{\alpha }^{\alpha +\beta }\left({t}_{0},\upgamma \right).\) We obtain a strengthening of the Plemelj–Privalov theorem for functions from the class \({H}_{\alpha }^{\alpha +\beta }\left({t}_{0},\upgamma \right).\) It is proved that, at the point t0 of increased smoothness for α+β < 1, there is only a logarithmic loss.
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References
V. V. Andrievskii, “On the question of the smoothness of an integral of Cauchy type,” Ukr. Mat. Zh., 38, No. 2, 139–149 (1986); English translation: Ukr. Mat. J., 38, No. 2, 123–126 (1986).
A. A. Babaev, “A singular integral with continuous density,” Azerb. Gos. Univ. Uch. Zap., Ser. Fiz.-Mat. Nauk, 5, 11–23 (1965).
A. A. Babaev and V. V. Salaev, “A one-dimensional singular operator with continuous density along a closed curve,” Dokl. Akad. Nauk SSSR, 209, 1257–1260 (1973).
R. A. Blaya, J. B. Reyes, and B. Kats, “Cauchy integral and singular integral operator over closed Jordan curves,” Monatsh. Math., 176, 1–15 (2015).
E. M. Dyn’kin, “On the smoothness of integrals of Cauchy type,” Sov. Mat. Dokl., 21, 199–202 (1980); English translation: Dokl. Akad. Nauk SSSR, 250, 794–797 (1980).
E. M. Dyn’kin, “Smoothness of Cauchy-type integrals,” Zap. Nauch. Sem. Leningrad. Otdel. Mat. Inst. AN Steklov. (LOMI), 92, 115–133 (1979).
N. A. Davydov, “The continuity of the Cauchy-type integral in a closed region,” Dokl. Akad. Nauk SSSR, 64, No. 6, 759–762 (1949).
G. David, “Operateurs integraux singulers sur certaines courbes du plan complexe,” Ann. Sci. Éc. Norm. Supér. (4), 17, No. 1, 157–189 (1984).
P. L. Duren, Theory of Hp-Spaces, Academic Press, New York (1970).
G. Freid, “An approximation theoretical study of the structure of real functions,” Studia Sci. Math. Hungar., 5, 141–150 (1970).
G. M. Goluzin, “Geometric theory of functions of a complex variable,” Transl. Math. Monogr., 26, AMS, Providence, RI (1968).
O. F. Gerus, “Moduli of smoothness of the Cauchy-type integral on regular curves,” J. Nat. Geom., 16, No. 1-2, 49–70 (1999).
E. G. Guseinov, “Plemelj–Privalov theorem for generalized Hölder classes,” Mat. Sb., 183, No. 2, 21–37 (1992).
V. P. Havin, “Continuity in Lp of an integral operator with Cauchy kernel,” Vestn. Leningrad. Univ., 22, No. 7 (1967).
A. Yu. Karlovich and I. M. Spitkovsky, “The Cauchy singular operator on weighted variable Lebesgue spaces,” Oper. Theory Adv. Appl., 236, 275–291 (1992).
V. M. Kokilashvili, V. Paatasvili, and S. Samko, “Boundary value problems for analytic functions in the class of Cauchy type integrals with density in Lp(.)(Γ),” Bound. Value Probl., 2005, 43–71 (2005).
V. M. Kokilashvili and S. Samko, “Weighted boundedness in Lebesgue spaces with variable exponents of classical operators on Carleson curves,” Proc. A. Razmadze Math. Inst., 138, 106–110 (2005).
V. Kokilashvili and S. G. Samko, “Singular integrals in weighted Lebesgue spaces with variable exponent,” Georg. Math. J., 10, No. 1, 145–156 (2003).
V. Kokilashvili and S. Samko, “Singular integrals and potentials in some Banach function spaces with variable exponent,” J. Funct. Spaces, 1, No. 1, 45–59 (2003).
V. M. Kokilashvili, “Boundedness criteria for singular integrals in weighted grand Lebesgue spaces,” J. Math. Sci. (N.Y.), 170, No. 3, 20–33 (2010).
V. M. Kokilashvili and A. Meskhi, “Boundedness of maximal and singular operators in Morrey spaces with variable exponent,” Armen. J. Math., 1, No. 1, 18–28 (2008).
B. A. Kats, “The Cauchy integral along _-rectifiable curves,” Lobachevskii J. Math., 7, 15–29 (2000).
B. A. Kats, “On a generalization of a theorem of N. A. Davydov,” Izv. Vyssh. Uchebn. Zaved., Ser. Mat., 1, 39–44 (2002); English translation: Russian Math. (Izv. VUZ.), 46, No. 1, 37–42 (2002).
B. A. Kats, “The Cauchy integral over non-rectifiable pats,” Contemp. Math., 455, 183–196 (2008).
B. A. Kats, “The Cauchy transform of certain distributions with application,” Complex Anal. Oper. Theory, 6, No. 6, 1147–1156 (2012).
L. Magnaradze, “On a generalization of the theorem of Plemelj–Privalov,” Soobshch. Akad. Nauk Gruzin. SSR, 8, 509–516 (1947).
J. I. Mamedkhanov and V. V. Salaev, “O new classes of functions related to the local structure of singular integrals and some approximation in them,” in: Abstr. of the All-Union Symp. on Approximation Theory (1980), pp. 91–92.
J. I. Mamedkhanov and I. B. Dadashova, “On one theorem of G. Freud,” Ukr. Math. Zh., 70, No. 11, 1578–1584 (2018); English translation: Ukr. Math. J., 70, No. 11, 1821–1828 (2019).
N. I. Muskhelishvili, Singular Integral Equations, 3rd ed., Wolters-Noordhoff Publ., Groningen (1967).
P. Mattila, “Rectifiability, analytic capacity, and singular integral,” Doc. Math. J. DMV, Extra Vol. ICM Berlin II, 509–516 (1998).
P. Mattila, “Singular integrals, analytic capacity, and rectifiability,” J. Fourier Anal. Appl., 3, 797–812 (1997).
P. Mattila, M. S. Melnikov, and J. Verdera, “The Cauchy integral, analytic capacity, and uniform rectifiability,” Ann. Math. (2), 144, No. 1, 127–136 (1996).
J. Plemelj, “Ein Erg¨anzungssatz zur Cauchyschen Integraldarstellung analytischer Funktionen, Randwerte betreffend,” Monatsh. Math. Phys., 19, 205–210 (1908).
J. Priwaloff, “Sur les fonctions conjuguées,” Bull. Soc. Math. France, 44, No. 2-3, 100–103 (1916).
J. Priwaloff, “Sur les intégrales du type de Cauchy,” C. R. (Doklady) Acad. Sci. URSS, 23, 859–863 (1939).
V. A. Paatashvili and G. A. Khuskivadze, “Boundedness of a singular Cauchy operator in Lebesgue spaces in the case of nonsmooth contours,” Trudy Tbilis. Mat. Inst. Razmadze Akad. Nauk Gruz. SSR, 69, 93–107 (1982).
J. B. Reyes and R. A. Blaya, “One-dimensional singular equations,” Complex Var. Theory Appl., 48, No. 6, 483–493 (2003).
R. M. Rahimov, “Behavior of an integral of Cauchy type “near” the line of integration,” Azerb. Gos. Univ. Uchen. Zap., 1, 51–59 (1979).
M. Sallay, “Über eine lokale Variante des Priwalowschen Satzes,” Studia Sci. Math. Hungar., 6, 427–429 (1971).
V. V. Salaev, “Direct and inverse estimates for a singular Cauchy integral along a closed curve,” Math. Notes, 19, No. 3, 221–231 (1976).
V. V. Salaev and A. O. Tokov, “Necessary and sufficient conditions for the continuity of Cauchy type integral in closed domain,” Dokl. Akad. Nauk Azerb. SSR, 39, No. 12, 7–11 (1983).
V. V. Salaev, E. G. Guseinov, and R. K. Seifullaev, “The Plemelj–Privalov theorem,” Dokl. Akad. Nauk SSSR, 315, No. 4, 790–793 (1990); English translation: Sov. Math. Dokl., 42, No. 3, 849–852 (1991).
T. S. Salimov, “A singular Cauchy integral in Hω spaces,” in: Theory of Functions and Approximations, Pt 2, Saratov (1982), pp. 130–134.
T. S. Salimov, “The singular Cauchy integral in space Lp, p ≥ 1,” Dokl. Akad. Nauk Azerb. SSR, 41, No. 3, 3–5 (1985).
S. G. Samko, “On a progress in the theory of Lebesgue spaces with variable exponent: maximal and singular operators,” Integral Transforms Spec. Funct., 16, No. 5-6, 461–482 (2005).
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Published in Ukrains’kyi Matematychnyi Zhurnal, Vol. 74, No. 5, pp. 614–627, May, 2023. Ukrainian DOI: https://doi.org/10.37863/umzh.v75i5.6959.
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Mamedkhanov, J.I., Jafarov, S.Z. On Local Properties of Singular Integrals. Ukr Math J 75, 703–718 (2023). https://doi.org/10.1007/s11253-023-02224-4
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DOI: https://doi.org/10.1007/s11253-023-02224-4