Pointwise estimates of polynomials orthogonal on a circle with respect to a weight not belonging to the spaces $L^r$ ($r>1$).
Trudy Instituta matematiki i mehaniki, Trudy Instituta Matematiki i Mekhaniki UrO RAN, Tome 15 (2009) no. 1, pp. 66-78 Cet article a éte moissonné depuis la source Math-Net.Ru

Voir la notice du chapitre de livre

Two-sided pointwise estimates are established for polynomials that are orthogonal on the circle $|z|=1$ with the weight $\varphi(\tau):=h(\tau)|\sin(\tau/2)|^{-1}g(|\sin(\tau/2)|)$ ($\tau\in\mathbb R$), where $g(t)$ is a concave modulus of continuity slowly changing at zero such that $t^{-1}g(t)\in L^1[0,1]$ and $h(\tau)$ is a positive function from the class $C_{2\pi}$ with a modulus of continuity satisfying the integral Dini condition. The obtained estimates are applied to find the order of the distance from the point $t=1$ to the greatest zero of a polynomial orthogonal on the segment [-1,1].
Mots-clés : orthogonal polynomials
Keywords: pointwise estimates, the Szegő function.
@article{TIMM_2009_15_1_a5,
     author = {V. M. Badkov},
     title = {Pointwise estimates of polynomials orthogonal on a~circle with respect to a~weight not belonging to the spaces $L^r$ ($r>1$).},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {66--78},
     year = {2009},
     volume = {15},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2009_15_1_a5/}
}
TY  - JOUR
AU  - V. M. Badkov
TI  - Pointwise estimates of polynomials orthogonal on a circle with respect to a weight not belonging to the spaces $L^r$ ($r>1$).
JO  - Trudy Instituta matematiki i mehaniki
PY  - 2009
SP  - 66
EP  - 78
VL  - 15
IS  - 1
UR  - http://geodesic.mathdoc.fr/item/TIMM_2009_15_1_a5/
LA  - ru
ID  - TIMM_2009_15_1_a5
ER  - 
%0 Journal Article
%A V. M. Badkov
%T Pointwise estimates of polynomials orthogonal on a circle with respect to a weight not belonging to the spaces $L^r$ ($r>1$).
%J Trudy Instituta matematiki i mehaniki
%D 2009
%P 66-78
%V 15
%N 1
%U http://geodesic.mathdoc.fr/item/TIMM_2009_15_1_a5/
%G ru
%F TIMM_2009_15_1_a5
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 Instituta matematiki i mehaniki, Trudy Instituta Matematiki i Mekhaniki UrO RAN, Tome 15 (2009) no. 1, pp. 66-78. http://geodesic.mathdoc.fr/item/TIMM_2009_15_1_a5/

[1] Badkov V. M., “Asimptoticheskoe povedenie ortogonalnykh mnogochlenov”, Mat. sb., 109(151):1(5) (1979), 46–59 | MR | Zbl

[2] Badkov V. M., “Priblizhenie funktsii v ravnomernoi metrike summami Fure po ortogonalnym polinomam”, Tr. MIAN, 145, 1980, 20–62 | MR | Zbl

[3] Badkov V. M., “Ravnomernye asimptoticheskie predstavleniya ortogonalnykh mnogochlenov”, Priblizhenie funktsii polinomami i splainami, UNTs AN SSSR, Sverdlovsk, 1985, 41–53 | MR

[4] Badkov V. M., “Asimptoticheskie i ekstremalnye svoistva ortogonalnykh polinomov pri nalichii osobennostei u vesa”, Tr. MIAN, 198, 1992, 41–88 | Zbl

[5] Badkov V. M., “Asimptotika mnogochlenov vtorogo roda i dvustoronnie potochechnye otsenki ikh proizvodnykh”, Tr. In-ta matematiki i mekhaniki UrO RAN, 1, Ekaterinburg, 1992, 71–83 | MR | Zbl

[6] Badkov V. M., “Potochechnye otsenki snizu modulei proizvodnykh mnogochlena, ortogonalnogo na okruzhnosti s vesom, imeyuschim osobennosti”, Mat. sb., 186:6 (1995), 3–14 | MR | Zbl

[7] Badkov V. M., “O nulyakh ortogonalnykh mnogochlenov”, Tr. In-ta matematiki i mekhaniki UrO RAN, 11, no. 2, Ekaterinburg, 2005, 30–46 | MR | Zbl

[8] Badkov V. M., Vvedenie v edinuyu teoriyu algebraicheskikh i trigonometricheskikh ortogonalnykh polinomov, ucheb. posobie, Izd-vo Ural. un-ta, Ekaterinburg, 2006, 132 pp. | MR

[9] Badkov V. M., “Ob osobennostyakh vesa, otnositelno kotorogo ortogonalny mnogochleny vtorogo roda”, Izv. TulGU, 2008, no. 1, 6–18, Tula, Izd-vo TulGU

[10] Badkov V. M., “Asimptotika naibolshego nulya mnogochlena, ortogonalnogo na otrezke s neklassicheskim vesom”, Tr. In-ta matematiki i mekhaniki UrO RAN, 14, no. 3, 2008, 38–42

[11] Geronimus Ya. L., Mnogochleny, ortogonalnye na okruzhnosti i na otrezke, Fizmatgiz, M., 1958, 240 pp. | Zbl

[12] Segë G., Ortogonalnye mnogochleny, Fizmatgiz, M., 1962, 500 pp.

[13] Seneta E., Pravilno menyayuschiesya funktsii, Nauka, M., 1985, 144 pp. | MR | Zbl

[14] Badkov V. M., “Equiconvergence of Fourier sums in orthogonal polynomials”, Proc. Steklov Inst. Math., Suppl. 1, 2004, S101–S127 | MR