Geodesic
On the operator Lipschitz norm of the functions $z^n$ on a finite set of the unit circle
Zapiski Nauchnykh Seminarov POMI, Investigations on linear operators and function theory. Part 49, Tome 503 (2021), pp. 5-21 
A. B. Aleksandrov. On the operator Lipschitz norm of the functions $z^n$ on a finite set of the unit circle. Zapiski Nauchnykh Seminarov POMI, Investigations on linear operators and function theory. Part 49, Tome 503 (2021), pp. 5-21. http://geodesic.mathdoc.fr/item/ZNSL_2021_503_a0/
@article{ZNSL_2021_503_a0,
     author = {A. B. Aleksandrov},
     title = {On the operator {Lipschitz} norm of the functions $z^n$ on a finite set of the unit circle},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {5--21},
     year = {2021},
     volume = {503},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2021_503_a0/}
}
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Voir la notice du chapitre de livre provenant de la source Math-Net.Ru

The paper contains some remarks concerning of the behavior of the operator Lipschitz norm of the functions $z^n$ on subsets of the unit circle. In particular, we prove that the operator Lipschitz norm of the restriction $z^n$ on a subset $\Lambda$ of the unit circle is equal to $|n|$ if and only if $\Lambda$ contains at least $2|n|$ elements.

[1] A. B. Aleksandrov, “Neskolko zamechanii ob operatorno lipshitsevykh funktsiyakh”, Zap. nauchn. semin. POMI, 480, 2019, 26–47 | MR

[2] A. B. Aleksandrov, V. V. Peller, “Operatorno lipshitsevy funktsii”, UMN, 71:4(430) (2016), 3–106 | MR | Zbl

[3] G. Bennett, “Schur multipliers”, Duke Math. J., 44 (1977), 603–639 | DOI | MR | Zbl