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Region of variability for functions with positive real part

Saminathan Ponnusamy, Allu Vasudevarao (2010)

Annales Polonici Mathematici

For γ ∈ ℂ such that |γ| < π/2 and 0 ≤ β < 1, let γ , β denote the class of all analytic functions P in the unit disk with P(0) = 1 and R e ( e i γ P ( z ) ) > β c o s γ in . For any fixed z₀ ∈ and λ ∈ ̅, we shall determine the region of variability V ( z , λ ) for 0 z P ( ζ ) d ζ when P ranges over the class ( λ ) = P γ , β : P ' ( 0 ) = 2 ( 1 - β ) λ e - i γ c o s γ . As a consequence, we present the region of variability for some subclasses of univalent functions. We also graphically illustrate the region of variability for several sets of parameters.

Region of variability for spiral-like functions with respect to a boundary point

S. Ponnusamy, A. Vasudevarao, M. Vuorinen (2009)

Colloquium Mathematicae

For μ ∈ ℂ such that Re μ > 0 let μ denote the class of all non-vanishing analytic functions f in the unit disk with f(0) = 1 and R e ( 2 π / μ z f ' ( z ) / f ( z ) + ( 1 + z ) / ( 1 - z ) ) > 0 in . For any fixed z₀ in the unit disk, a ∈ ℂ with |a| ≤ 1 and λ ∈ ̅, we shall determine the region of variability V(z₀,λ) for log f(z₀) when f ranges over the class μ ( λ ) = f μ : f ' ( 0 ) = ( μ / π ) ( λ - 1 ) a n d f ' ' ( 0 ) = ( μ / π ) ( a ( 1 - | λ | ² ) + ( μ / π ) ( λ - 1 ) ² - ( 1 - λ ² ) ) . In the final section we graphically illustrate the region of variability for several sets of parameters.

Regular and limit sets for holomorphic correspondences

S. Bullett, C. Penrose (2001)

Fundamenta Mathematicae

Holomorphic correspondences are multivalued maps f = Q ̃ Q ̃ - 1 : Z W between Riemann surfaces Z and W, where Q̃₋ and Q̃₊ are (single-valued) holomorphic maps from another Riemann surface X onto Z and W respectively. When Z = W one can iterate f forwards, backwards or globally (allowing arbitrarily many changes of direction from forwards to backwards and vice versa). Iterated holomorphic correspondences on the Riemann sphere display many of the features of the dynamics of Kleinian groups and rational maps, of which...

Régularité et suprarégularité pour une famille de germes dirichlétiens (par rapport à un support de référence)

Maurice Blambert, Jean Siméon (1969)

Annales de l'institut Fourier

Définitions et propriétés des notions nouvelles de demi-plans, droites et abscisses de régularité et de suprarégularité pour une famille de germes dirichlétiens, par rapport à un support commun de référence. Conditions suffisantes (du type de Landau-Fekete) d’égalité de ces abscisses et expressions algorithmiques de majorants. Relations de dépendance (du type de V. Bernstein) entre les différentes abscisses considérées d’une famille donnée. Extensions de résultats classiques relatifs à la famille...

Currently displaying 61 – 80 of 163