Abstract
By using the Schur test, we give some upper and lower estimates on the norm of a composition operator on \(\mathcal {H}^2\), the space of Dirichlet series with square summable coefficients, for the inducing symbol \(\varphi (s)=c_1+c_{q}q^{-s}\) where \(q\ge 2\) is a fixed integer. We also give an estimate on the approximation numbers of such an operator.
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Appel, M.J., Bourdon, P.S., Thrall, J.J.: Norms of composition operators on the Hardy space. Exp. Math. 5(2), 111–117 (1996)
Bayart, F.: Compact composition operators on a Hilbert space of Dirichlet series. Ill. J. Math. 47(3), 725–743 (2003)
Bayart, F.: Composition operators on the polydisk induced by affine maps. J. Funct. Anal. 260(7), 1969–2003 (2011)
Brevig, O.F.: Sharp norm estimates for composition operators and Hilbert-type inequalities. Bull. Lond. Math. Soc. 49(6), 965–978 (2017)
Carl, B., Stephani, I.: Entropy, Compactness and the Approximation of Operators. Cambridge University Press, Cambridge (1990)
Clifford, J.H., Dabkowski, M.G.: Singular values and Schmidt pairs of composition operators on the Hardy space. J. Math. Anal. Appl. 305(1), 183–196 (2005)
Cowen, C.C.: Linear fractional composition operators on $H^2$. Integral Equ. Oper. Theory 11(2), 151–160 (1988)
Cowen, C.C., MacCluer, B.D.: Composition Operators on Spaces of Analytic Functions. CRC Press, Boca Raton (1995)
Gordon, J., Hedenmalm, H.: The composition operators on the space of Dirichlet series with square summable coefficients. Mich. Math. J. 46(2), 313–329 (1999)
Halmos, P.R.: A Hilbert Space Problem Book, 2nd edn. Springer, New York (1982)
Hammond, C.: The norm of a composition operator with linear symbol acting on the Dirichlet space. J. Math. Anal. Appl. 303(2), 499–508 (2005)
Hedenmalm, H.: Dirichlet series and functional analysis. In: Laudal, O.A., Piene, R. (eds.) The legacy of Niels Henrik Abel. Springer, Berlin, Heidelberg (2004)
Hedenmalm, H., Lindqvist, P., Seip, K.: A Hilbert space of Dirichlet series and systems of dilated functions in $L^{2}(0,1)$. Duke Math. J. 86(1), 1–37 (1997)
Hlawka, E., Schoissengeier, J., Taschner, R.: Geometric and Analytic Number Theory. Springer, Berlin (1991)
Hurst, P.R.: Relating composition operators on different weighted Hardy spaces. Arch. Math. (Basel) 68(6), 503–513 (1997)
Lavrik, A.F.: On the main term of the divisor’s problem and the power series of the Riemann’s zeta function in a neighbourhood of its pole. Trudy Mat. Inst. Akad. Nauk. SSSR 142, 165–173 (1976). (in Russian)
Ponnusamy, S.: Foundations of Mathematical Analysis. Springer, New York (2012)
Queffélec, H.: Norms of composition operators with affine symbols. J. Anal. 20, 47–58 (2012)
Queffélec, H., Seip, K.: Approximation numbers of composition operators on the $H^2$ space of Dirichlet series. J. Funct. Anal. 268(6), 1612–1648 (2015)
Zhu, K.: Operator Theory in Function Spaces. Mathematical Surveys and Monographs, vol. 138, 2nd edn. American Mathematical Society, Providence (2007)
Acknowledgements
The authors thank the referee for many useful comments. The first author thanks the Council of Scientific and Industrial Research (CSIR), India, for providing financial support in the form of a SPM Fellowship to carry out this research. The third author thanks the Indian Statistical Institute of Chennai for providing good and friendly working conditions in December 2015, when this collaboration was initiated. The second author is currently at ISI Chennai.
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Muthukumar, P., Ponnusamy, S. & Queffélec, H. Estimate for Norm of a Composition Operator on the Hardy–Dirichlet Space. Integr. Equ. Oper. Theory 90, 11 (2018). https://doi.org/10.1007/s00020-018-2434-x
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DOI: https://doi.org/10.1007/s00020-018-2434-x