TY - JOUR
T1 - On C. Michel's hypothesis about the modulus of typically real polynomials
AU - Dmitrishin, Dmitriy
AU - Smorodin, Andrey
AU - Stokolos, Alex
N1 - Publisher Copyright:
© 2023
PY - 2023/5
Y1 - 2023/5
N2 - Extremal problems for typically real polynomials go back to a paper by W. W. Rogosinski and G. Szegő, where a number of problems were posed, which were partially solved by using orthogonal polynomials. Since then, not too many new results on extremal properties of typically real polynomials have been obtained. Fundamental work in this direction is due to M. Brandt, who found a novel way of solving extremal problems. In particular, he solved C. Michel's problem of estimating the modulus of a typically real polynomial of odd degree. On the other hand, D. K. Dimitrov showed the efficiency of Fejér's method for solving the Rogosinski–Szegő problems. In this article, we completely solve Michel's problem by using Fejér's method.
AB - Extremal problems for typically real polynomials go back to a paper by W. W. Rogosinski and G. Szegő, where a number of problems were posed, which were partially solved by using orthogonal polynomials. Since then, not too many new results on extremal properties of typically real polynomials have been obtained. Fundamental work in this direction is due to M. Brandt, who found a novel way of solving extremal problems. In particular, he solved C. Michel's problem of estimating the modulus of a typically real polynomial of odd degree. On the other hand, D. K. Dimitrov showed the efficiency of Fejér's method for solving the Rogosinski–Szegő problems. In this article, we completely solve Michel's problem by using Fejér's method.
KW - Extremal trigonometric polynomials
KW - Fejér method
KW - Typically real polynomials
UR - http://www.scopus.com/inward/record.url?scp=85150445710&partnerID=8YFLogxK
U2 - 10.1016/j.jat.2023.105885
DO - 10.1016/j.jat.2023.105885
M3 - Article
AN - SCOPUS:85150445710
SN - 0021-9045
VL - 289
JO - Journal of Approximation Theory
JF - Journal of Approximation Theory
M1 - 105885
ER -