On the conjecture of Hayami and Owa concerning the class R(α)

In the paperwe discuss the functional Φf(μ) ≡ a2a4 − μa23 for functions in the class R(α), α ϵ [0, 1). This class consists of analytic functions which satisfy the condition Re f’ (z) > α for all z in the unit disk Δ.We show that the conjecture of Hayami and Owa [1], that is, |Φf(μ)| ≤ (1 − α)2 · max{ 1/2 – 4/9μ, 4/9μ} for all f ϵ R(α) and μ ϵ R, is false. Moreover, we find estimates of |Φf(μ)| that improve the results obtained by Hayami and Owa.

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Opracowanie ze środków MNiSW w ramach umowy 812/P-DUN/2016 na działalność upowszechniającą naukę (zadania 2017).