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On asymptotic critical values and the Rabier Theorem

Zbigniew Jelonek (2004)

Banach Center Publications

Let X ⊂ kⁿ be a smooth affine variety of dimension n-r and let f = ( f , . . . , f m ) : X k m be a polynomial dominant mapping. It is well-known that the mapping f is a locally trivial fibration outside a small closed set B(f). It can be proved (using a general Fibration Theorem of Rabier) that the set B(f) is contained in the set K(f) of generalized critical values of f. In this note we study the Rabier function. We give a few equivalent expressions for this function, in particular we compare this function with the Kuo function...

On blowing up versal discriminants

Piotr Jaworski (1998)

Banach Center Publications

It is well-known that the versal deformations of nonsimple singularities depend on moduli. The first step in deeper understanding of this phenomenon is to determine the versal discriminant, which roughly speaking is an obstacle for analytic triviality of an unfolding or deformation along the moduli. The goal of this paper is to describe the versal discriminant of Z k , 0 and Q k , 0 singularities basing on the fact that the deformations of these singularities may be obtained as blowing ups of certain deformations...

On Bochner-Martinelli residue currents and their annihilator ideals

Mattias Jonsson, Elizabeth Wulcan (2009)

Annales de l’institut Fourier

We study the residue current R f of Bochner-Martinelli type associated with a tuple f = ( f 1 , , f m ) of holomorphic germs at 0 C n , whose common zero set equals the origin. Our main results are a geometric description of R f in terms of the Rees valuations associated with the ideal ( f ) generated by f and a characterization of when the annihilator ideal of R f equals ( f ) .

On condition ( a f ) of a stratified mapping

Satoshi Koike (1983)

Annales de l'institut Fourier

For a stratified mapping f , we consider the condition ( a f ) concerning the kernel of the differential of f . We show that the condition ( a f ) is equivalent to the condition ( a f S ) which has a more obvious geometric content.

On Fatou-Julia decompositions

Taro Asuke (2013)

Annales de la faculté des sciences de Toulouse Mathématiques

We propose a Fatou-Julia decomposition for holomorphic pseudosemigroups. It will be shown that the limit sets of finitely generated Kleinian groups, the Julia sets of mapping iterations and Julia sets of complex codimension-one regular foliations can be seen as particular cases of the decomposition. The decomposition is applied in order to introduce a Fatou-Julia decomposition for singular holomorphic foliations. In the well-studied cases, the decomposition behaves as expected.

On geometry of fronts in wave propagations

Susumu Tanabé (1999)

Banach Center Publications

We give a geometric descriptions of (wave) fronts in wave propagation processes. Concrete form of defining function of wave front issued from initial algebraic variety is obtained by the aid of Gauss-Manin systems associated with certain complete intersection singularities. In the case of propagations on the plane, we get restrictions on types of possible cusps that can appear on the wave front.

On gradient at infinity of semialgebraic functions

Didier D'Acunto, Vincent Grandjean (2005)

Annales Polonici Mathematici

Let f: ℝⁿ → ℝ be a C² semialgebraic function and let c be an asymptotic critical value of f. We prove that there exists a smallest rational number ϱ c 1 such that |x|·|∇f| and | f ( x ) - c | ϱ c are separated at infinity. If c is a regular value and ϱ c < 1 , then f is a locally trivial fibration over c, and the trivialisation is realised by the flow of the gradient field of f.

On Halphen’s Theorem and some generalizations

Alcides Lins Neto (2006)

Annales de l’institut Fourier

Let M n be a germ at 0 m of an irreducible analytic set of dimension n , where n 2 and 0 is a singular point of M . We study the question: when does there exist a germ of holomorphic map φ : ( n , 0 ) ( M , 0 ) such that φ - 1 ( 0 ) = { 0 } ? We prove essentialy three results. In Theorem 1 we consider the case where M is a quasi-homogeneous complete intersection of k polynomials F = ( F 1 , ... , F k ) , that is there exists a linear holomorphic vector field X on m , with eigenvalues λ 1 , ... , λ m + such that X ( F T ) = U · F T , where U is a k × k matrix with entries in 𝒪 m . We prove that if there exists...

On higher dimensional Hirzebruch-Jung singularities.

Patrick Popescu-Pampu (2005)

Revista Matemática Complutense

A germ of normal complex analytical surface is called a Hirzebruch-Jung singularity if it is analytically isomorphic to the germ at the 0-dimensional orbit of an affine toric surface. Two such germs are known to be isomorphic if and only if the toric surfaces corresponding to them are equivariantly isomorphic. We extend this result to higher-dimensional Hirzebruch-Jung singularities, which we define to be the germs analytically isomorphic to the germ at the 0-dimensional orbit of an affine toric...

On homological index

Bahman Khanedani (2000)

Annales de la Faculté des sciences de Toulouse : Mathématiques

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