259 research outputs found
Continuity of the Green function in meromorphic families of polynomials
We prove that along any marked point the Green function of a meromorphic
family of polynomials parameterized by the punctured unit disk explodes
exponentially fast near the origin with a continuous error term.Comment: Modified references. Added a corollary about the adelic metric
associated with an algebraic family endowed with a marked poin
The dynamical Manin-Mumford problem for plane polynomial automorphisms
Let be a polynomial automorphism of the affine plane. In this paper we
consider the possibility for it to possess infinitely many periodic points on
an algebraic curve . We conjecture that this happens if and only if
admits a time-reversal symmetry; in particular the Jacobian
must be a root of unity.
As a step towards this conjecture, we prove that the Jacobian of and all
its Galois conjugates lie on the unit circle in the complex plane. Under mild
additional assumptions we are able to conclude that indeed is
a root of unity. We use these results to show in various cases that any two
automorphisms sharing an infinite set of periodic points must have a common
iterate, in the spirit of recent results by Baker-DeMarco and Yuan-Zhang.Comment: 45 pages. Theorems A and B are now extended to automorphisms defined
over any field of characteristic zer
Degree growth of monomial maps and McMullen's polytope algebra
We compute all dynamical degrees of monomial maps by interpreting them as
mixed volumes of polytopes. By exploiting further the isomorphism between the
polytope algebra of P. McMullen and the universal cohomology of complete toric
varieties, we construct invariant positive cohomology classes when the
dynamical degrees have no resonance.Comment: 26 pages. Minor modification
Eigenvaluations
We study the dynamics in C^2 of superattracting fixed point germs and of
polynomial maps near infinity. In both cases we show that the asymptotic
attraction rate is a quadratic integer, and construct a plurisubharmonic
function with the adequate invariance property. This is done by finding an
infinitely near point at which the map becomes rigid: the critical set is
contained in a totally invariant set with normal crossings. We locate this
infinitely near point through the induced action of the dynamics on a space of
valuations. This space carries an real-tree structure and conveniently encodes
local data: an infinitely near point corresponds to a open subset of the tree.
The action respects the tree structure and admits a fixed point--or
eigenvaluation--which is attracting in a certain sense. A suitable basin of
attraction corresponds to the desired infinitely near point.Comment: 48 pages, 2 figures, To appear in Annales de l'EN
Webs invariant by rational maps on surfaces
We prove that under mild hypothesis rational maps on a surface preserving
webs are of Latt\`es type. We classify endomorphisms of P^2 preserving webs,
extending former results of Dabija-Jonsson.Comment: 27 pages, submitte
Holomorphic self-maps of singular rational surfaces
We give a new proof of the classification of normal singular surface germs
admitting non-invertible holomorphic self-maps and due to J. Wahl. We then draw
an analogy between the birational classification of singular holomorphic
foliations on surfaces, and the dynamics of holomorphic maps. Following this
analogy, we introduce the notion of minimal holomorphic model for holomorphic
maps. We give sufficient conditions which ensure the uniqueness of such a
model.Comment: 37 pages. To appear in Publicacions Matematiques
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