Complex Monge-Amp Research Articles

The strong topology of ω-plurisubharmonic functions

On $(X,\omega)$ compact K\"ahler manifold, given a model type envelope $\psi\in PSH(X,\omega)$ (i.e. a singularity type) we prove that the Monge-Amp\`ere operator is an homeomorphism between the set of $\psi$-relative finite energy potentials and the set of $\psi$-relative energy measures endowed with their strong topologies given as the coarsest refinements of the weak topologies such that the relative energies become continuous. Moreover, given a totally ordered family $\mathcal{A}$ of model type envelopes with positive total mass representing different singularities types, the sets $X_{\mathcal{A}}, Y_{\mathcal{A}}$ given respectively as the union of all $\psi$-relative finite energy potentials and of all $\psi$-relative finite energy measures varying $\psi\in\overline{\mathcal{A}}$ have two natural strong topologies which extends the strong topologies on each component of the unions. We show that the Monge-Amp\`ere operator produces an homeomorphism between $X_{\mathcal{A}}$ and $Y_{\mathcal{A}}$. As an application we also prove the strong stability of a sequence of solutions of prescribed complex Monge-Amp\`ere equations when the measures have uniformly $L^{p}$-bounded densities for $p>1$ and the prescribed singularities are totally ordered.

Quasi-plurisubharmonic envelopes 2: Bounds on Monge–Ampère volumes

In \cite{GL21a} we have developed a new approach to $L^{\infty}$-a priori estimates for degenerate complex Monge-Amp\`ere equations, when the reference form is closed. This simplifying assumption was used to ensure the constancy of the volumes of Monge-Amp\`ere measures. We study here the way these volumes stay away from zero and infinity when the reference form is no longer closed. We establish a transcendental version of the Grauert-Riemenschneider conjecture, partially answering conjectures of Demailly-P\u{a}un \cite{DP04} and Boucksom-Demailly-P\u{a}un-Peternell \cite{BDPP13}. Our approach relies on a fine use of quasi-plurisubharmonic envelopes. The results obtained here will be used in \cite{GL21b} for solving degenerate complex Monge-Amp\`ere equations on compact Hermitian varieties.

C1,1 regularity of degenerate complex Monge–Ampère equations and some applications

In this paper, we prove a $C^{1,1}$ estimate for solutions of complex Monge-Amp\`{e}re equations on compact almost Hermitian manifolds. Using this $C^{1,1}$ estimate, we show existence of $C^{1,1}$ solutions to the degenerate Monge-Amp\`{e}re equations, the corresponding Dirichlet problems and the singular Monge-Amp\`{e}re equations. We also study the singularities of the pluricomplex Green's function. In addition, the proof of the above $C^{1,1}$ estimate is valid for a kind of complex Monge-Amp\`{e}re type equations. As a geometric application, we prove the $C^{1,1}$ regularity of geodesics in the space of Sasakian metrics.

C1,1 regularity of geodesics of singular Kähler metrics

We show the optimal $C^{1,1}$ regularity of geodesics in nef and big cohomology class on K\"ahler manifolds away from the non-K\"ahler locus, assuming sufficiently regular initial data. As a special case, we prove the $C^{1,1}$ regularity of geodesics of K\"ahler metrics on compact K\"ahler varieties away from the singular locus. Our main novelty is an improved boundary estimate for the complex Monge-Amp\`ere equation that does not require strict positivity of the reference form near the boundary. We also discuss the case of some special geodesic rays.

The complex Monge–Ampère equation with a gradient term

We consider the complex Monge-Amp\`ere equation with an additional linear gradient term inside the determinant. We prove existence and uniqueness of solutions to this equation on compact Hermitian manifolds.

Pluripotential Kähler–Ricci flows

We develop a parabolic pluripotential theory on compact K{\"a}hler manifolds, defining and studying weak solutions to degenerate parabolic complex Monge-Amp{\`e}re equations. We provide a parabolic analogue of the celebrated Bedford-Taylor theory and apply it to the study of the K{\"a}hler-Ricci flow on varieties with log terminal singularities.

Some results on the complex Monge-Ampère equation

The complex Monge-Ampere equation has been the subject ofintensive studies in the past fifty years, since its significant applications in complex analysis, complex geometry and Kahler geometry. In this paper, we will introduce our recent work on the Liouville type theorem, $C^{1,~\\alpha}$ and $C^{2,~\\alpha~}$ estimates of the complex Monge-Ampere equation and its applications in Sasakian geometry. These works are joint with S. Dinew, P. F. Guan, C. Li, J. Y. Li and X. W. Zhang.

On the Hölder continuous subsolution problem for the complex Monge–Ampère equation, II

We solve the Dirichlet problem for the complex Monge-Amp\`ere equation on a strictly pseudoconvex with the right hand side being a positive Borel measure which is dominated by the Monge-Amp\`ere measure of a H\"older continuous plurisubharmonic function. If the boundary data is continuous, then the solution is continuous. If the boundary is H\"older continuous, then the solution is also H\"older continuous. In particular, the answer to a question of A. Zeriahi is always affirmative.

Viscosity solutions to parabolic complex Monge–Ampère equations

In this paper, we study the Cauchy-Dirichlet problem for Parabolic complex Monge-Amp\`ere equations on a strongly pseudoconvex domain by the viscosity method. We extend the results in [EGZ15b] on the existence of solution and the convergence at infinity. We also establish the H\"older regularity of the solutions when the Cauchy-Dirichlet data are H\"older continuous.

Projective logarithmic potentials

We study the projective logarithmic potential $G_\mu$ of a Probability measure $\mu$ on the complex projective space ${P}^{n}$ equiped with the Fubini-Study metric $\omega$. We prove that the Green operator $G $ has strong regularizing properties. It was shown by the second author that the range of the operator $G$ is contained in the (local) domain of definition of the complex Monge-Amp\`ere operator on $P^n$. This result extends earlier results by Carlehed. We will show that the complex Monge-Amp\`ere measure of the logarithmic potential of $\mu$ is absolutely continuous with respect to the Lebesgue measure on $P^n$ if and only if the measure $\mu$ has no atoms. Moreover when the measure $\mu$ has a positive dimension, we give more precise results on regularity properties of the potential $G_\mu$ in terms of the dimension of $\mu$.

A Remark on the Continuous Subsolution Problem for the Complex Monge-Amp\xe8re Equation

We prove that if the modulus of continuity of a plurisubharmonic subsolution satisfies a Dini-type condition then the Dirichlet problem for the complex Monge-Ampère equation has the continuous solution. The modulus of continuity of the solution also given if the right hand side is locally dominated by capacity.

Quasi-asymptotically conical Calabi–Yau manifolds

We construct new examples of quasi-asymptotically conical (QAC) Calabi-Yau manifolds that are not quasi-asymptotically locally Euclidean (QALE). We do so by first providing a natural compactification of QAC-spaces by manifolds with fibred corners and by giving a definition of QAC-metrics in terms of an associated Lie algebra of smooth vector fields on this compactification. Thanks to this compactification and the Fredholm theory for elliptic operators on QAC-spaces developed by the second author and Mazzeo, we can in many instances obtain K\"ahler QAC-metrics having Ricci potential decaying sufficiently fast at infinity. This allows us to obtain QAC Calabi-Yau metrics in the K\"ahler classes of these metrics by solving a corresponding complex Monge-Amp\`ere equation.

Complex Monge-Ampère Equation in Strictly Pseudoconvex Domains

We study the complex Monge-Amp\`ere equation $(dd^c u)^n=\mu$ in a strictly pseudoconvex domain $\Omega$ with the boundary condition $u=\varphi$, where $\varphi\in C(\partial\Omega)$. We provide a non-trivial sufficient condition for continuity of the solution $u$ outside "small sets".

Expansion formula for complex Monge–Ampère equation along cone singularities

In this paper, we prove the asymptotic expansion of the solutions to some singular complex Monge-Amp\`ere equation which arise naturally in the study of the conical K\"ahler-Einstein metric.

Plurisubharmonic envelopes and supersolutions

We make a systematic study of (quasi-)plurisubharmonic envelopes on compact K\ahler manifolds, as well as on domains of $\mathbb{C}^n$, by using and extending an approximation process due to Berman [Ber13]. We show that the quasi-psh envelope of a viscosity super-solution is a pluripotential super-solution of a given complex Monge-Amp\`ere equation. We use these ideas to solve complex Monge-Amp\`ere equations by taking lower envelopes of super-solutions.

The conical complex Monge–Ampère equations on Kähler manifolds

In this paper, by providing the uniform gradient estimates for a sequence of the approximating equations, we prove the existence, uniqueness and regularity of the conical parabolic complex Monge-Amp\`ere equation with weak initial data. As an application, we prove a regularity estimates, that is, any $L^{\infty}$-solution of the conical complex Monge-Amp\`ere equation admits the $C^{2,\alpha,\beta}$-regularity.

Regularizing properties of complex Monge–Ampère flows II: Hermitian manifolds

We prove that a general complex Monge-Amp\`ere flow on a Hermitian manifold can be run from an arbitrary initial condition with zero Lelong number at all points. Using this property, we confirm a conjecture of Tosatti-Weinkove: the Chern-Ricci flow performs a canonical surgical contraction. Finally, we study a generalization of the Chern-Ricci flow on compact Hermitian manifolds, namely the twisted Chern-Ricci flow.

$$C^{2,\alpha }$$ C 2 , α regularities and estimates for nonlinear elliptic and parabolic equations in geometry

We give sharp $C^{2,\alpha}$ estimates for solutions of some fully nonlinear elliptic and parabolic equations in complex geometry and almost complex geometry, assuming a bound on the Laplacian of the solution. We also prove the analogous results to complex Monge-Amp\`{e}re equations with conical singularities. As an application, we obtain a local estimate for Calabi-Yau equation in almost complex geometry. We also improve the $C^{2,\alpha}$ regularities and estimates for viscosity solutions to some uniformly elliptic and parabolic equations. All our results are optimal regarding the H\"{o}lder exponent.

Geodesics in the space of Kähler cone metrics, I

In this paper, we study the Dirichlet problem of the geodesic equation in the space of K\"ahler cone metrics ${\cal H}_{\cal B}$; that is equivalent to a homogeneous complex Monge-Amp\`ere equation whose boundary values consist of K\"ahler metrics with cone singularities. Our approach concerns the generalization of the function space defined by Donaldson to the case of K\"ahler manifolds with boundary; moreover we introduce a subspace ${\cal H}_C$ of ${\cal H}_{\cal B}$ which we define by prescribing appropriate geometric conditions. Our main result is the existence, uniqueness and regularity of $C^{1,1}_{\cal B}$ geodesics whose boundary values lie in ${\cal H}_C$. Moreover, we prove that such geodesic is the limit of a sequence of $C^{2, \alpha}_{\cal B}$ approximate geodesics under the $C^{1,1}_{\cal B}$-norm. As a geometric application, we prove the metric space structure of ${\cal H}_C$.

Parabolic complex Monge–Ampère type equations on closed Hermitian manifolds

We study the parabolic complex Monge-Amp\`ere type equations on closed Hermitian manfolds. We derive uniform $C^\infty$ {\em a priori} estimates for normalized solutions, and then prove the $C^\infty$ convergence. The result also yields a way to carry out method of continuity for elliptic Monge-Amp\'ere type equations.