01.01.01 (Real analysis, complex analysis, and functional analysis)
Birth date:
16.05.1940
Keywords:
polynomials orthogonal on a segment; polynomials orthogonal on a circle; trigonometric polynomials orthogonal with respect to a weight; weights with non-classical singularities; asymptotic and approximation properties of orthogonal polynomials; the best approximations of the Szeg\ddot{o} function; weight analogs of Markov, Bernstein and Jackson–Nikol'skii inequalities.
Subject:
Uniform asymptotic representations on all range of orthogonality for generalized Jacobi polynomials orthogonal on a circle or a segment and also for trigonometric are obtained. Some questions on (uniform, mean and almost everywhere) convergence of Fourier series with respect to the mentioned polynomials are investigated. Two-sided point-wise estimations (sometimes uniform asymptotic representations) in terms of the Szego function for polynomials orthonormal on a circle (and their derivatives) with respect to a weight (introduced by the author), which orders of singularities are defined by finite products of real powers of concave moduli of continuity. In some cases orders of the best approximations (by algebraic polynomials) of the corresponding Szego function are found.
Biography
Graduated from Faculty of Mathematics and Mechanics of I. I. Mechnikov Odessa State University in 1962 (department of differential equations). Ph.D. thesis was defended in 1969. D.Sci. thesis was defended in 1995. A list of my works contains more than 60 titles.
Main publications:
Badkov V. M. Approksimativnye svoistva ryadov Fure po ortogonalnym polinomam // UMN, 1978, 33 (4), 51–106.
Badkov V. M. Priblizhenie funktsii v ravnomernoi metrike summami Fure po ortogonalnym polinomam // Trudy MIAN, 1980, 145, 20–62.
Badkov V. M. Ravnomernye asimptoticheskie predstavleniya ortogonalnykh polinomov // Trudy MIAN, 1983, 164, 3–36.
Badkov V. M. Asimptoticheskie i ekstremalnye svoistva ortogonalnykh polinomov // Trudy MIRAN, 1992, 198, 41–88.
Badkov V. M. Potochechnye otsenki snizu modulei proizvodnykh mnogochlena, ortogonalnogo na okruzhnosti s vesom, imeyuschim osobennosti // Matem. sbornik, 1995, 186 (6), 3–14.
V. M. Badkov, “Asymptotic properties of zeros of orthogonal trigonometric polynomials of half-integer orders”, Trudy Inst. Mat. i Mekh. UrO RAN, 19:2 (2013), 54–70
2012
2.
V. M. Badkov, “Asymptotic formulae for the zeros of orthogonal polynomials”, Mat. Sb., 203:9 (2012), 3–14; Sb. Math., 203:9 (2012), 1231–1243
V. M. Badkov, “Trigonometric analogs of the Szegő equiconvergence theorem for Fourier–Jacobi series”, Trudy Inst. Mat. i Mekh. UrO RAN, 18:4 (2012), 68–79
2011
4.
V. M. Badkov, “Estimates of the Lebesgue function of Fourier sums over trigonometric polynomials orthogonal with a weight not belonging to the spaces $L^r$$(r>1)$”, Trudy Inst. Mat. i Mekh. UrO RAN, 17:3 (2011), 71–82; Proc. Steklov Inst. Math. (Suppl.), 277, suppl. 1 (2012), 21–32
V. M. Badkov, “Some properties of Jacobi polynomials orthogonal on a circle”, Trudy Inst. Mat. i Mekh. UrO RAN, 16:4 (2010), 65–73; Proc. Steklov Inst. Math. (Suppl.), 273, suppl. 1 (2011), S49–S58
2009
6.
V. M. Badkov, “Pointwise estimates of polynomials orthogonal on a circle with respect to a weight not belonging to the spaces $L^r$ ($r>1$).”, Trudy Inst. Mat. i Mekh. UrO RAN, 15:1 (2009), 66–78; Proc. Steklov Inst. Math. (Suppl.), 265, suppl. 1 (2009), S64–S77
V. M. Badkov, “Asymptotic behavior of the maximal zero of a polynomial orthogonal on a segment with a nonclassical weight”, Trudy Inst. Mat. i Mekh. UrO RAN, 14:3 (2008), 38–42; Proc. Steklov Inst. Math. (Suppl.), 264, suppl. 1 (2009), S39–S43
V. M. Badkov, “Orders of the weighted Lebesgue constants for Fourier sums with respect to orthogonal polynomials”, Trudy Inst. Mat. i Mekh. UrO RAN, 7:1 (2001), 47–61; Proc. Steklov Inst. Math. (Suppl.), 2001no. , suppl. 1, S48–S64
V. M. Badkov, “Maclaurin's expansion of Szegö's function whose weight is positive and satisfies Dini's condition, uniformly converges in the closed disc”, Trudy Inst. Mat. i Mekh. UrO RAN, 5 (1998), 199–204
1995
11.
V. M. Badkov, “Pointwise estimates from below of the moduli of the derivatives of orthogonal polynomials on of the derivatives of orthogonal polynomials on”, Mat. Sb., 186:6 (1995), 3–14; Sb. Math., 186:6 (1995), 771–781
V. M. Badkov, “Asymptotics of the second kind polynomials and above and below point estimates of its derivatives”, Trudy Inst. Mat. i Mekh. UrO RAN, 1 (1992), 71–83
V. M. Badkov, “Asymptotic and extremal properties of orthogonal polynomials corresponding to weight having singularities”, Trudy Mat. Inst. Steklov., 198 (1992), 41–88; Proc. Steklov Inst. Math., 198 (1994), 37–82
V. M. Badkov, “Systems of orthogonal polynomials explicitly represented by the Jacobi polynomials”, Mat. Zametki, 42:5 (1987), 650–659; Math. Notes, 42:5 (1987), 858–863
V. M. Badkov, “Uniform asymptotic representations of orthogonal polynomials and their derivatives”, Trudy Mat. Inst. Steklov., 180 (1987), 36–38; Proc. Steklov Inst. Math., 180 (1989), 39–41
V. M. Badkov, “Approximation of functions in a uniform metric by Fourier sums in orthogonal polynomials”, Trudy Mat. Inst. Steklov., 145 (1980), 20–62; Proc. Steklov Inst. Math., 145 (1981), 19–65
V. M. Badkov, “Approximation properties of Fourier series in orthogonal polynomials”, Uspekhi Mat. Nauk, 33:4(202) (1978), 51–106; Russian Math. Surveys, 33:4 (1978), 53–117
V. M. Badkov, “Convergence in the mean and almost everywhere of Fourier series in polynomials orthogonal on an interval”, Mat. Sb. (N.S.), 95(137):2(10) (1974), 229–262; Math. USSR-Sb., 24:2 (1974), 223–256
V. M. Badkov, “Convergence in the mean of the Fourier series in orthogonal polynomials”, Mat. Zametki, 14:2 (1973), 161–172; Math. Notes, 14:2 (1973), 651–657
V. M. Badkov, “Approximation of functions by partial sums of Fourier series in polynomials orthogonal on an interval”, Mat. Zametki, 8:4 (1970), 431–441; Math. Notes, 8:4 (1970), 712–717
V. M. Badkov, “The uniform convergence of fourier series in orthogonal polynomials”, Mat. Zametki, 5:3 (1969), 285–295; Math. Notes, 5:3 (1969), 174–179
V. M. Badkov, “Approximation of functions by partial sums of a Fourier series of generalized Jacobi polynomials”, Mat. Zametki, 3:6 (1968), 671–682; Math. Notes, 3:6 (1968), 428–435
V. M. Badkov, “Estimates of the Lebesgue function and the remainder of a Fourier–Jacobi series”, Sibirsk. Mat. Zh., 9:6 (1968), 1263–1283; Siberian Math. J., 9:6 (1968), 947–962