arXiv subjects

Ahmed Zeriahi

Publications and source records attributed to Ahmed Zeriahi.

46 records · Page 3Linked to original sources

arXiv2011

Hölder continuous solutions to Monge-Ampère equations

Let $(X,ω)$ be a compact Kähler manifold. We obtain uniform Hölder regularity for solutions to the complex Monge-Ampère equation on $X$ with $L^p$ right hand side, $p>1$. The same regularity is furthermore proved on the ample locus in any big cohomology class. We also study the range $\MAH(X,ω)$ of the complex Monge-Ampère operator acting on $ω$-plurisubharmonic Hölder continuous functions. We show that this set is convex, by sharpening Kołodziej's result that measures with $L^p$-density belong to $\MAH(X,ω)$ and proving that $\MAH(X,ω)$ has the "$L^p$-property", $p>1$. We also describe accurately the symmetric measures it contains.

math.CV↗

arXiv2010

Extension of plurisubharmonic functions with growth control

Suppose that $X$ is an analytic subvariety of a Stein manifold $M$ and that $φ$ is a plurisubharmonic (psh) function on $X$ which is dominated by a continuous psh exhaustion function $u$ of $M$. Given any number $c>1$, we show that $φ$ admits a psh extension to $M$ which is dominated by $cu$ on $M$. We use this result to prove that any $ω$-psh function on a subvariety of the complex projective space is the restriction of a global $ω$-psh function, where $ω$ is the Fubini-Study Kähler form.

math.CV↗

arXiv2010

Viscosity solutions to degenerate Complex Monge-Ampère equations

We develop an alternative approach to Degenerate complex Monge-Ampère equations on compact Kähler manifolds based on the concept of viscosity solutions and compare systematically viscosity concepts with pluripotential theoretic ones. We generalize to the Kähler case a theorem due to Dinew and Zhang in the projective case to the effect that their pluripotential solutions constructed previously by the authors are continuous.

math.AG↗

arXiv2008

Singular Kahler-Einstein metrics

We study degenerate complex Monge-Ampère equations of the form $(ω+dd^c φ)^n = e^{t φ} μ$ where $ω$ is a big semi-positive form on a compact Kähler manifold $X$ of dimension $n$, $t \in \R^+$, and $μ=fω^n$ is a positive measure with density $f\in L^p(X,ω^n)$, $p>1$. We prove the existence and unicity of bounded $ω$-plurisubharmonic solutions. We also prove that the solution is continuous under a further technical condition. In case $X$ is projective and $ω=ψ^*ω'$, where $ψ:X\to V$ is a proper birational morphism to a normal projective variety, $[ω']\in NS_{\R} (V)$ is an ample class and $μ$ has only algebraic singularities, we prove that the solution is smooth in the regular locus of the equation. We use these results to construct singular Kähler-Einstein metrics of non-positive curvature on projective klt pairs, in particular on canonical models of algebraic varieties of general type.

math.AG↗

arXiv2007

Domains of definition of Monge-Ampère operators on compact Kähler manifolds

Let $(X,ω)$ be a compact Kähler manifold. We introduce and study the largest set $DMA(X,ω)$ of $ω$-plurisubharmonic (psh) functions on which the complex Monge-Ampère operator is well defined. It is much larger than the corresponding local domain of definition, though still a proper subset of the set $PSH(X,\om)$ of all $\om$-psh functions. We prove that certain twisted Monge-Ampère operators are well defined for all $ω$-psh functions. As a consequence, any $\om$-psh function with slightly attenuated singularities has finite weighted Monge-Ampère energy.

math.CV↗

arXiv2007

The weigthed Monge-Ampère energy of quasiplurisubharmonic functions

We study degenerate complex Monge-Ampère equations on a compact Kähler manifold $(X,ω)$. We show that the complex Monge-Ampère operator $(ω+ dd^c \cdot)^n$ is well-defined on the class ${\mathcal E}(X,ω)$ of $ω$-plurisubharmonic functions with finite weighted Monge-Ampère energy. The class ${\mathcal E}(X,ω)$ is the largest class of $ω$-psh functions on which the Monge-Ampère operator is well-defined and the comparison principle is valid. It contains several functions whose gradient is not square integrable. We give a complete description of the range of the Monge-Ampère operator $(ω+dd^c \cdot)^n$ on ${\mathcal E}(X,ω)$, as well as on some of its subclasses. We also study uniqueness properties, extending Calabi's result to this unbounded and degenerate situation, and we give applications to complex dynamics and to the existence of singular Kähler-Einstein metrics.

math.CV↗

arXiv2007

A minimum principle for plurisubharmonic functions

The main goal of this work is to give new and precise generalizations to various classes of plurisubharmonic functions of the classical minimum modulus principle for holomorphic functions of one complex variable, in the spirit of the famous lemma of Cartan-Boutroux. As an application we obtain precise estimates on the size of "plurisubharmonic lemniscates" in terms of appropriate Hausdorff contents.

math.CV↗

arXiv2006

Hölder continuous solutions to Monge-Ampère equations

We study the regularity of solutions to complex Monge-Ampère equations $(dd^c u)^n=f dV$, on bounded strongly pseudoconvex domains $ Ω\subset \C^n$. We show, under a mild technical assumption, that the unique solution $u$ to such an equation is Hölder continuous if the boundary values $ϕ$ are Hölder continuous and the density $f$ belongs to $L^p(Ω)$ for some $p>1$. This improves previous results by Bedford-Taylor and Kolodziej.

math.CV↗

arXiv2006

Monge-Ampère operators on compact Kähler manifolds

We study the complex Monge-Amp\` ere operator on compact Kähler manifolds. We give a complete description of its range on the set of $ω-$plurisubharmonic functions with $L^2$ gradient and finite self energy, generalizing to this compact setting results of U.Cegrell from the local pluripoltential theory. We give some applications to complex dynamics and to the existence of Kähler-Einstein metrics on singular manifolds.

math.CV↗

arXiv2005

Intrinsic capacities on compact Kähler manifolds

We study fine properties of quasiplurisubharmonic functions on compact Kähler manifolds. We define and study several intrinsic capacities which characterize pluripolar sets and show that locally pluripolar sets are globally "quasi-pluripolar".

math.CV↗