Displaying 21 – 40 of 105

Showing per page

Composition operators: N α to the Bloch space to Q β

Jie Xiao (2000)

Studia Mathematica

Let N α ,B and Qβ be the weighted Nevanlinna space, the Bloch space and the Q space, respectively. Note that B and Q β are Möbius invariant, but N α is not. We characterize, in function-theoretic terms, when the composition operator C ϕ f = f ϕ induced by an analytic self-map ϕ of the unit disk defines an operator C ϕ : N α B , B Q β , N α Q β which is bounded resp. compact.

Deux exemples sur la dimension moyenne d’un espace de courbes de Brody

Bernardo Freitas Paulo da Costa (2013)

Annales de l’institut Fourier

On étudie la dimension moyenne de l’espace de courbes 1 -Brody à valeurs dans deux surfaces complexes  : d’abord pour des surfaces de Hopf, et ensuite pour P 2 privé d’une droite. On montre dans le premier cas que la dimension moyenne est nulle via une borne sur la croissance des fonctions holomorphes faisant apparaître le lemme de la dérivée logarithmique. Pour montrer la positivité dans le deuxième exemple, on relève de la droite à son complémentaire un espace de courbes de Brody de dimension moyenne...

Entire function sharing two polynomials with its k th derivative

Sujoy Majumder, Nabadwip Sarkar (2024)

Mathematica Bohemica

We investigate the uniqueness problem of entire functions that share two polynomials with their k th derivatives and obtain some results which improve and generalize the recent result due to Lü and Yi (2011). Also, we exhibit some examples to show that the conditions of our results are the best possible.

Entire functions that share a function with their first and second derivatives

Feng Lü, Junfeng Xu (2012)

Annales Polonici Mathematici

Applying the normal family theory and the theory of complex differential equations, we obtain a uniqueness theorem for entire functions that share a function with their first and second derivative, which generalizes several related results of G. Jank, E. Mues & L. Volkmann (1986), C. M. Chang & M. L. Fang (2002) and I. Lahiri & G. K. Ghosh (2009).

Generalized Cesàro operators on certain function spaces

Sunanda Naik (2010)

Annales Polonici Mathematici

Motivated by some recent results by Li and Stević, in this paper we prove that a two-parameter family of Cesàro averaging operators b , c is bounded on the Dirichlet spaces p , a . We also give a short and direct proof of boundedness of b , c on the Hardy space H p for 1 < p < ∞.

Holomorphic motions commuting with semigroups

Zbigniew Słodkowski (1996)

Studia Mathematica

A holomorphic family f z , |z|<1, of injections of a compact set E into the Riemann sphere can be extended to a holomorphic family of homeomorphisms F z , |z|<1, of the Riemann sphere. (An earlier result of the author.) It is shown below that there exist extensions F z which, in addition, commute with some holomorphic families of holomorphic endomorphisms of ̅ ̅ ̅ ̅ ̅ ̅ f z ( E ) , |z|<1 (under suitable assumptions). The classes of covering maps and maps with the path lifting property are discussed.

Currently displaying 21 – 40 of 105