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This article is cited in 15 scientific papers (total in 16 papers)
Theory of factorization of functions meromorphic in the disk
M. M. Dzhrbashyan
Abstract:
The factorization of functions of the class $N$ of functions meromorphic in the disk has been established in the well-known theorem due to R. Nevanlinna.
In a monograph the author has constructed a theory of factorization of a family of classes $N_\alpha$ of functions meromorphic in the disk $|z|<1$, which classes are monotonically increasing with increasing $\alpha$ ($-1<\alpha<+\infty$) and in addition $N_0=N$.
In the present work, a complete theory of factorization is established, which essentially can be applied to arbitrarily restricted or arbitrarily broad classes of meromorphic functions in the disk $|z|<1$.
By applying the generalized operator $L^{(\omega)}$ of Riemann–Liouville type associated with an arbitrary positive continuous function $\omega(x)$ on $[0,1)$, $\omega(x)\in L(0,1)$ ($\omega(0)=1$), a general formula of Jensen–Nevanlinna type is established which relates the values of a meromorphic function to the distribution of its zeros and its poles.
This formula leads, essentially, to a new concept of the $\omega$-characteristic function $T_\omega(r)$ in the class $N\{\omega\}$ of bounded $\omega$-characteristic, and of functions $B_\omega(z;z_k)\in N\{\omega\}$ with zeros $\{z_k\}_1^\infty$ which satisfy the condition $\sum_{k=1}^\infty\int_{|z_k|}^1\omega(x)\,dx<+\infty$.
Finally, in a series of theorems, parametric representations of the classes $N\{\omega\}$, as well as of the more restricted classes $A\{\omega\}$ of functions analytic in the disk, are established. Also their boundary properties are determined. Along with the above it is proved that every function $F(z)\notin N$ meromorphic in the unit disk belongs to some class $N\{\omega\}$, and hence admits a suitable factorization.
Bibliography: 17 titles.
Received: 03.01.1969
Citation:
M. M. Dzhrbashyan, “Theory of factorization of functions meromorphic in the disk”, Mat. Sb. (N.S.), 79(121):4(8) (1969), 517–615; Math. USSR-Sb., 8:4 (1969), 493–592
Linking options:
https://www.mathnet.ru/eng/sm3601https://doi.org/10.1070/SM1969v008n04ABEH002044 https://www.mathnet.ru/eng/sm/v121/i4/p517
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Abstract page: | 1044 | Russian version PDF: | 243 | English version PDF: | 13 | References: | 92 |
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