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Antonio Alarcon

Publications and source records attributed to Antonio Alarcon.

66 records · Page 4Linked to original sources
arXiv2012

Minimal surfaces in $\mathbb{R}^3$ properly projecting into $\mathbb{R}^2$

For all open Riemann surface M and real number $θ\in (0,π/4),$ we construct a conformal minimal immersion $X=(X_1,X_2,X_3):M \to \mathbb{R}^3$ such that $X_3+\tan(θ) |X_1|:M \to \mathbb{R}$ is positive and proper. Furthermore, $X$ can be chosen with arbitrarily prescribed flux map. Moreover, we produce properly immersed hyperbolic minimal surfaces with non empty boundary in $\mathbb{R}^3$ lying above a negative sublinear graph.

math.DG↗
arXiv2011

Harmonic diffeomorphisms between domains in the Euclidean 2-sphere

We study the existence or not of harmonic diffeomorphisms between certain domains in the Euclidean 2-sphere. In particular, we show harmonic diffeomorphisms from circular domains in the complex plane onto finitely punctured spheres, with at least two punctures. This result follows from a general existence theorem for maximal graphs in the Lorentzian product $M\times\mathbb{R}_1,$ where $M$ is an arbitrary $n$-dimensional compact Riemannian manifold, $n\geq 2.$ In contrast, we show that there is no harmonic diffeomorphism from the unit complex disc onto the once punctured sphere and no harmonic diffeomeorphisms from finitely punctured spheres onto circular domains in the Euclidean 2-sphere.

math.DG↗
arXiv2011

On harmonic quasiconformal immersions of surfaces in $\mathbb{R}^3$

This paper is devoted to the study of the global properties of harmonically immersed Riemann surfaces in $\mathbb{R}^3.$ We focus on the geometry of complete harmonic immersions with quasiconformal Gauss map, and in particular, of those with finite total curvature. We pay special attention to the construction of new examples with significant geometry.

math.DG↗
arXiv2011

Compact complete null curves in Complex 3-space

We prove that for any open orientable surface $S$ of finite topology, there exist a Riemann surface $\mathcal{M},$ a relatively compact domain $M\subset\mathcal{M}$ and a continuous map $X:\bar{M}\to\mathbb{C}^3$ such that: $\mathcal{M}$ and $M$ are homeomorphic to $S,$ $\mathcal{M}-M$ and $\mathcal{M}-\bar{M}$ contain no relatively compact components in $\mathcal{M},$ $X|_M$ is a complete null holomorphic curve, $X|_{\bar{M}-M}:\bar{M}-M\to\mathbb{C}^3$ is an embedding and the Hausdorff dimension of $X(\bar{M}-M)$ is $1.$ Moreover, for any $ε>0$ and compact null holomorphic curve $Y:N\to\mathbb{C}^3$ with non-empty boundary $Y(\partial N),$ there exist Riemann surfaces $M$ and $\mathcal{M}$ homeomorphic to $N^\circ$ and a map $X:\bar{M}\to\mathbb{C}^3$ in the above conditions such that $δ^H(Y(\partial N),X(\bar{M}-M))<ε,$ where $δ^H(\cdot,\cdot)$ means Hausdorff distance in $\mathbb{C}^3.$

math.DG↗
arXiv2010

Harmonic mappings and conformal minimal immersions of Riemann surfaces into $\mathbb{R}^n$

We prove that for any open Riemann surface $N,$ natural number $n\geq 3,$ non-constant harmonic map $h:N\to \mathbb{R}^{n-2}$ and holomorphic 2-form $H$ on $N,$ there exists a weakly complete harmonic map $X=(X_j)_{j=1,\ldots,n}:N \to \mathbb{R}^n$ with Hopf differential $H$ and $(X_j)_{j=3,\ldots,n}=h.$ In particular, there exists a complete conformal minimal immersion $Y=(Y_j)_{j=1,\ldots,n}:N \to \mathbb{R}^n$ such that $(Y_j)_{j=3,\ldots,n}=h.$ As a consequence of these results, complete full non-decomposable minimal surfaces with arbitrary conformal structure and whose generalized Gauss map is non-degenerate and fails to intersect $n$ hyperplanes of $\mathbb{CP}^{n-1}$ in general position are constructed. Moreover, complete non-proper embedded minimal surfaces in $\mathbb{R}^n,$ $\forall n>3,$ are exhibited.

math.DG↗
arXiv2009

Complete minimal surfaces and harmonic functions

We prove that for any open Riemann surface $M$ and any non constant harmonic function $h:M \to \mathbb{R},$ there exists a complete conformal minimal immersion $X:M \to \mathbb{R}^3$ whose third coordinate function coincides with $h.$ As a consequence, complete minimal surfaces with arbitrary conformal structure and whose Gauss map misses two points are constructed.

math.DG↗
arXiv2009

Proper harmonic maps from hyperbolic Riemann surfaces into the Euclidean plane

Let $Σ$ be a compact Riemann surface and $D_1,...,D_n$ a finite number of pairwise disjoint closed disks of $Σ$. We prove the existence of a proper harmonic map into the Euclidean plane from a hyperbolic domain $Ω$ containing $Σ\backslash\cup_{j=1}^n D_j$ and of its topological type. Here, $Ω$ can be chosen as close as necessary to $Σ\backslash\cup_{j=1}^n D_j$. In particular, we obtain proper harmonic maps from the unit disk into the Euclidean plane, which disproves a conjecture posed by R. Schoen and S.T. Yau.

math.DG↗
arXiv2009

Compact complete minimal immersions in R^3

In this paper we find, for any arbitrary finite topological type, a compact Riemann surface $\mathcal{M},$ an open domain $M\subset\mathcal{M}$ with the fixed topological type, and a conformal complete minimal immersion $X:M\to\R^3$ which can be extended to a continuous map $X:\bar{M}\to\R^3,$ such that $X_{|\partial M}$ is an embedding and the Hausdorff dimension of $X(\partial M)$ is $1.$ We also prove that complete minimal surfaces are dense in the space of minimal surfaces spanning a finite set of closed curves in $\R^3$, endowed with the topology of the Hausdorff distance.

math.DG↗
arXiv2008

Complete minimal surfaces in R3 with a prescribed coordinate function

In this paper we construct complete simply connected minimal surfaces with a prescribed coordinate function. Moreover, we prove that these surfaces are dense in the space of all minimal surfaces with this coordinate function (with the topology of the smooth convergence on compact sets).

math.DG↗
arXiv2007

On the Calabi-Yau problem for maximal surfaces in L^3

In this paper we construct an example of a weakly complete maximal surface in the Lorentz-Minkowski space L^3, which is bounded by a hyperboloid. Moreover, all the singularities of our example are of lightlike type.

math.DG↗