Meromorphic functions and differences of subharmonic functions in integrals and the difference characteristic of Nevanlinna. I. Radial maximum growth characteristics (2104.07439v1)

Abstract: Let $f$ be a meromorphic function on the complex plane $\mathbb C$ with the maximum function of its modulus $M(r,f)$ on circles centered at zero of radius $r$. A number of classical, well-known and widely used results allow us to estimate from above the integrals of the positive part of the logarithm $\ln^+M(t,f)$ over subsets of $E\subset [0,r]$ via the Nevanlinna characteristic $T(r,f)$ and the linear Lebesgue measure of the set $E$. The paper gives similar estimates for the Lebesgue-Stieltjes integrals of $\ln^+M (t,f)$ over the increasing integration function of $m$. The main part of the presentation is conducted immediately for the differences of subharmonic functions on closed discs with the center at zero, i.e, $\delta$-subharmonic functions. The only condition in the main theorem is the Dini condition for the modulus of continuity of the integration function $m$. This condition is, in a sense, necessary. Thus, the first part of the work to a certain extent completes in a general form the research on the upper estimates of the integrals of the radial maximum growth characteristics of arbitrary meromorphic and $\delta$-subharmonic functions through the Nevanlinna characteristic with its versions and through the characteristics of the integration function $m$.