Study Kazdan-Warner equations on graphs using Brouwer degree theory.
problem Proving existence of solutions to Kazdan-Warner equations on finite graphs.
method Degree theory approach to uniformly bound and compute Brouwer degree.
result New proofs of existence results for Kazdan-Warner equations.
Two methods find at least two solutions to Kazdan-Warner's problem on surfaces.
problem Finding solutions to Kazdan-Warner's problem on two-dimensional surfaces.
method Direct method on convex sets and variational method of mountain pass.
result At least two solutions to the Kazdan-Warner's problem are found.
Solves generalized Kazdan-Warner equations on foliated manifolds.
problem Existence and uniqueness of solutions to generalized Kazdan-Warner equations on foliated manifolds.
method Extends theorem to compact foliated manifolds, provides examples of PDEs.
result Solves the transverse Hitchin equation and its generalizations.
Let G=(V,E) be a connected finite graph. In this short paper, we reinvestigate the Kazdan-Warner equation Δu=c−heu with c<0 on G, where h defined on V is a known function. Grigor'yan, Lin and Yang \cite{GLY} showed that if the Kazdan-Warner equation has a solution, then h, the average value …
Study identifies obstructions for solving a 4th-order boundary problem.
problem Solving a 4th-order boundary problem with specific curvature conditions.
method Derived Kazdan-Warner type identities using variational formulation and conformal variations.
result Obtained nontrivial integral obstructions to solvability.
Any 2-dim Riemannian manifold with spherical topology can be embedded isometrically into a lightcone of the Minkowski spacetime. We apply this fact to give a proof of the Kazdan-Warner identity.
Study on compact Kähler surfaces for sign-changing curvatures.
problem Prescribing sign-changing Chern scalar curvatures on compact Kähler surfaces.
method Established a Chen-Li type existence theorem and provided an alternative proof.
result Alternative proof of Ding-Liu's theorem on sign-changing Gaussian curvatures.
This paper solves the Christoffel problem in hyperbolic space and its equivalent on spheres.
problem Prescribing curvatures for convex hypersurfaces in hyperbolic space.
method Proving a full rank theorem to establish the existence of solutions.
result Existence of solutions to the Christoffel problem and its equivalent Nirenberg-Kazdan-Warner problem on spheres.
New equations on manifolds linked to torus actions, proving existence and uniqueness.
problem Existence and uniqueness of solutions for generalized Kazdan-Warner equations.
method Linear action of a torus on complex vector spaces, existence and uniqueness proof on compact manifolds.
result Existence and uniqueness of solutions for the generalized Kazdan-Warner equations.
New Kazdan-Warner problem for equivariant metrics on manifolds.
problem Equivariant scalar curvature functions on manifolds with group actions.
method Established equivariant analogue of Kazdan-Warner trichotomy.
result New class of totally G-positive pairs with positive constant scalar curvature.
Directly applies Kazdan--Warner results to prescribe scalar curvature on bundles.
problem Prescribing scalar curvature functions on bundles.
method Direct application of Kazdan--Warner results and variational methods.
result Determines which functions are realizable as scalar curvature functions on bundles.
Global existence and convergence proved for Kazdan-Warner equation with non-negative prescribed function.
problem Existence and convergence of solutions to the Kazdan-Warner equation on a closed Riemann surface.
method Global existence and convergence proved using additional assumptions on the prescribed function and the geometry of the surface.
result Global existence and convergence of solutions proved under specific conditions.
The Kazdan-Warner problem is solved for Riemann surfaces with smooth boundaries.
problem Realizing smooth functions as Gaussian and geodesic curvatures on compact Riemann surfaces.
method Existence results of Brezis-Merle type equations and uniformization theorem extension.
result Any smooth function on compact Riemann surface with smooth boundary can be realized as a Gaussian curvature function and any on the boundary as a geodesic curvature function.
We study the limiting behaviour of solutions to abelian vortex equations when the volume of the underlying Riemann surface grows to infinity. We prove that the solutions converge smoothly away from finitely many points. The proof relies on a priori estimates for functions satisfying generalised Kazdan-Warner equations.…
Study noncompact manifolds' Chern scalar curvatures, proving existence and multiplicity.
problem Prescribing Chern scalar curvatures on noncompact manifolds.
method Solving a Kazdan-Warner type equation on noncompact non-Kähler manifolds with an analytic condition.
result Established existence results and provided a new proof of multiplicity theorem.
The paper tackles prescribing discrete Gaussian curvature on polyhedral surfaces.
problem Prescribing discrete Gaussian curvature on polyhedral surfaces.
method Discrete conformal theory and variational principles with constraints.
result Proves Kazdan-Warner type theorems for polyhedral surfaces.
The paper proves existence of solutions to Kazdan-Warner equations on finite graphs.
problem Existence of solutions to Kazdan-Warner equations on finite graphs.
method Variational methods and eigenvalue analysis.
result The paper proves the existence of solutions to the Kazdan-Warner equations under various conditions.
We give a proof of the Kazdan-Warner conjecture concerning the prescribed scalar curvature problem in the null case.
In this note, we prove two Kazdan-Warner type identities involving v(2k), the renormalized volume coefficients of a Riemannian manifold (Mn,g), and G2r, the so-called Gauss-Bonnet curvature, and a conformal Killing vector field on (Mn,g). In the case when the Riemannian manifold is locally conformally f…
We solve the modified Kazdan-Warner problem of finding metrics with prescribed scalar curvature and unit total volume.
The paper solves curvature prescription problems on balls and disks.
problem Prescribing Gaussian and boundary geodesic curvature on a disk, and scalar and mean curvature on a ball.
method Ljapunov-Schmidt procedure for existence results.
result New existence results for prescribed functions close to constants.
The classical Pohozaev identity constrains potential solutions of certain semilinear PDE boundary value problems. The Kazdan-Warner identity is a similar necessary condition important for the Nirenberg problem of conformally prescribing scalar curvature on the sphere. For dimensions n≥3 both identities are captur…
We prove in this article that the local image of each conformal Q-curvature operator of arbitrary order on the sphere admits no scalar constraint. However, we prove that identities of Kazdan--Warner type hold for its graph.
The paper proves compactness of metrics on spheres with isolated singularities.
problem Compactness of metrics on spheres with isolated singularities.
method Proves compactness in Cm,α topology for metrics with constant σk curvature and positive lower bound on k-Dilational Pohozaev invariants. result Set of conformal metrics is locally compact in Cm,α topology. The paper proves a theorem for discretizing Gaussian curvature on surfaces.
problem Discretizing Gaussian curvature on surfaces with nonpositive Euler number.
method Discrete conformal theory and variational principles with constraints.
result Each decorated piecewise Euclidean metric on surfaces with nonpositive Euler number is discrete conformal to a metric with a specific discrete curvature constant.
Extends existence results for scalar curvature on conical manifolds.
problem Existence of metrics with positive scalar curvature on conical manifolds.
method Extends Kazdan-Warner and Cruz-Vitório results to conical manifolds with isolated singularities using index theory.
result Any bounded and smooth negative function on a conical manifold is the scalar curvature of some conical metric.
Let G=(V,E) be a connected finite graph and C(V) be the set of functions defined on V. Let Δp be the discrete p-Laplacian on G with p>1 and L=Δp−k, where k∈C(V) is positive everywhere. Consider the operator L:C(V)→C(V). We prove that −L is one to one, onto and preserves order. So i…
We obtain a Hitchin-Kobayashi-type correspondence for symplectic vortex equations, with the target a Kahler cone over a compact Sasakian manifold. We show that the correspondence reduces to studying the existence and uniqueness of Kazdan-Warner equations. Using this, we construct a map between the moduli space of solut…
In this paper, we consider the scalar curvature of Yamabe solitons. In particular we show that, with natural conditions and non positive Ricci curvature, any complete Yamabe soliton has constant scalar curvature, namely, it is a Yamabe metric. We also show that the quadratic decay at infinity of the Ricci curvature of …
In a previous paper, the authors showed that metrics which are asymptotic to Anti-de Sitter-Schwarzschild metrics with positive mass admit a unique foliation by stable spheres with constant mean curvature. In this paper we extend that result to all asymptotically hyperbolic metrics for which the trace of the mass term …
In this paper we introduce and study a geometric heat flow to find Killing vector fields on closed Riemannian manifolds with positive sectional curvature. We study its various properties, prove the global existence of the solution of this flow, discuss its convergence and possible applications, and its relation to the …
We prove a Pohozaev type identity for non-linear eigenvalue equations of the Dirac operator on Riemannian spin manifolds with boundary. As an application, we obtain that the mean curvature H of a conformal immersion S^{n}-> R^{n+1} satisfies ∫∂XH=0 where X is a conformal vector field on S^{n} and where t…
This paper is devoted to the existence of contact forms of prescribed Webster scalar curvature on a 3−dimensional CR compact manifold locally conformally CR equivalent to the unit sphere S3 of C2. Due to Kazdan-Warner type obstructions, conditions on the function H to be realized as a We…
The paper proves quasi-Einstein structures on manifolds admit Killing vector fields and provides new examples.
problem Classifying quasi-Einstein structures and understanding their properties.
method Analyzing quasi-Einstein equations and exploring their connections to Hitchin's equations.
result A class of quasi-Einstein structures on closed manifolds must admit a Killing vector field.
For a closed smooth manifold M admitting a symplectic structure, we define a smooth topological invariant Z(M) using almost-Kähler metrics, i.e. Riemannian metrics compatible with symplectic structures. We also introduce Z(M,[[ω]]) depending on symplectic deformation equivalence class [[ω]]. We first prove tha…
Sharp inequalities and extremals on compact Riemann surfaces with boundary.
problem Sharp Trudinger-Moser inequalities on compact Riemann surfaces with smooth boundary.
method Blow-up analysis involving isothermal coordinates.
result Existence of extremals and sharp inequalities.
The study examines metrics with unit volume or area on manifolds with boundaries, finding critical points and solving curvature problems.
problem Finding metrics with prescribed curvature on manifolds with boundaries.
method Variational properties of volume and boundary area functionals, using critical metrics and curvature conditions.
result Sufficient and necessary conditions for metrics to be critical points and for scalar/mean curvature functions.
The sigma invariant is studied for torus, K3 surface, and 3d manifolds.
problem Investigating the sigma invariant for specific manifolds.
method Analyzing isometric embeddings and scalar curvature functionals.
result Sigma invariant is zero for torus, K3 surface, and certain 3d manifolds.
The paper studies metrics with constant scalar curvature on foliated manifolds.
problem Existence of metrics with constant scalar curvature on foliated manifolds.
method Analysis of orbit-like foliations and application of Kondrakov Embedding Theorem.
result Existence of metrics with constant scalar curvature on foliated manifolds.
Analog to the classical result of Kazdan-Warner for the existence of solutions to the prescribed Gaussian curvature equation on compact 2-manifolds without boundary, it is widely known that if (M,g0) is a closed 4-manifold with zero Q-curvature and if f is any non-constant, smooth, sign-changing function with $\…
Our first objective in this paper is to give a natural formulation of the Christoffel problem for hypersurfaces in Hn+1, by means of the hyperbolic Gauss map and the notion of hyperbolic curvature radii for hypersurfaces. Our second objective is to provide an explicit equivalence of this Christoffel problem with t…
The paper solves a mean field equation on a compact Riemann surface using variational and blowup analysis.
problem Solving a specific mean field equation on a compact Riemann surface.
method Variational method and blowup analysis.
result Proves existence results in the critical case and identifies the blowup point.
Proves existence and compactness of solutions to σ2-Nirenberg problem on sphere.
problem Existence and compactness of solutions to σ2-Nirenberg problem on S2. method Establishes Liouville type theorems, a priori estimates, and uses degree theory.
result Proves existence of at most one blow-up point for solutions to σ2-Nirenberg problem. The paper solves conditions for prescribing scalar and Gauss curvatures on manifolds with zero first eigenvalue.
problem Conditions for prescribing scalar and Gauss curvatures on manifolds with zero first eigenvalue.
method Local variational methods, local Yamabe-type equations, and monotone iteration scheme.
result The necessary and sufficient conditions for prescribing scalar and Gauss curvatures are established.
The paper studies φ-static perfect fluid space-times in Einstein's General Relativity.
problem Analyzing the geometry of φ-static perfect fluid space-times. method Reduction of Einstein's Field Equations to the factors of a static warped product, introducing φ-curvatures. result Sharp sufficient conditions for a compact φ-SPFST with boundary to be isometric to the standard hemisphere. The study classifies manifolds based on their geometric properties and invariants.
problem Classifying manifolds based on their geometric and topological properties.
method Analyzing metrics through isometric embeddings and deformations, considering scalar curvature, Ricci tensor, and Einstein metrics.
result The KW type classification of manifolds and sigma invariant calculations.