Extended a formula to higher dimensions with singularities.
problem Generalizing a formula to higher dimensions with singularities.
method Extended a formula to all even dimensions n≥4 for a class of conformally flat manifolds with singular points.
result First formula in dimensions higher than two with isolated conical singularities.
Establishes refined singularity estimate for nonnegative n-superharmonic functions in locally conformally flat manifolds.
problem Analyzing volume growth and verifying Cohn-Vossen inequality in locally conformally flat manifolds.
method Refined singularity estimate and characterization of volume growth.
result Analytically characterizes volume growth and verifies Cohn-Vossen inequality.
Proves mass theorem for AF manifolds with conical singularities.
problem Proving the positive mass theorem for specific types of manifolds.
method Conformal blow up technique applied to AF manifolds with isolated conical singularities.
result Positive mass theorem proven for the specified manifolds.
In a joint work with Saji, the second and the third authors gave an intrinsic formulation of wave fronts and proved a realization theorem of wave fronts in space forms. As an application, we show that the following four objects are essentially same; * conformally flat n-manifolds (n>=3) with admissible singular points …
Proves positive mass theorem on conical manifolds with small angles.
problem Proving the positive mass theorem on conical manifolds with small cone angles.
method Analyzes conical manifolds with small cone angles, assuming spin structure and locally conformal flatness.
result Proves the positive mass theorem under specified conditions.
Local Lorentzian theorem preserves metrics or makes them flat.
problem Analyzing conformal vector fields on Lorentzian manifolds.
method Proves local isometry or conformal flatness using global arguments.
result Optimal improvement of conformal vector field normal forms.
The study proves constraints on the structure of compact half-conformally flat manifolds.
problem Analyzing the structure of compact half-conformally flat manifolds.
method Analyzes manifolds with bounded L2 energy, scalar curvature, and non-collapsing assumption. result Proves all Betti numbers are bounded for certain manifolds.
Study finds all local models for flat metrics with isolated singularities.
problem Understanding isolated singularities in flat metrics on Riemann surfaces.
method Complex Analysis to find local models and polynomial growth conditions.
result An isolated singularity of a flat metric with finite area is a conical one.
Investigates deformations of Q-curvature on manifolds.
problem Deformation problems of Q-curvature on closed Riemannian manifolds.
method Uses Q-singular space and derived several results about geometry related to Q-curvature. result Showed that any smooth function can be realized as a Q-curvature on generic Q-flat manifolds.
In this article, we prove several results about the extension to the boundary of conformal immersions from an open subset Ω of a Riemannian manifold L, into another Riemannian manifold N of the same dimension. In dimension n≥3, and when the (n−1)-dimensional Hausdorff measure of ∂Ω is zero, we …
Study on Yamabe flow convergence and singularities.
problem Understanding convergence and singularities in Yamabe flow solutions.
method Analysis of complete non-compact conformally flat solutions to the Yamabe flow.
result Existence of Type II singularities that develop either at a finite time or as to+∞. Proves Penrose inequality in all dimensions for specific manifolds.
problem Proving Penrose inequality in arbitrary dimensions for certain manifolds.
method Extends Bray's conformal-flow method to higher dimensions, dealing with singular outer-minimizing enclosures.
result Proves the Riemannian Penrose inequality in arbitrary dimensions.
Continuous metrics on manifolds with singularities are shown to be Einstein.
problem Classical theorem extension to singular metrics.
method Extending classical conformal geometry theorem to continuous metrics with singularities.
result Continuous metrics achieving the Yamabe invariant are Einstein away from singularities and can be extended smoothly.
The paper studies solutions to the Yamabe equation on asymptotically flat manifolds and their behavior at infinity.
problem Behavior of solutions to the Yamabe equation on asymptotically flat manifolds.
method Establishing asymptotic behavior near isolated singularities and using appropriate flatness conditions.
result Positive solutions on asymptotically flat manifolds of flatness order at least (n-2)/2 converge to fundamental solutions or radial Fowler solutions at infinity.
Green functions play an important role in conformal geometry. In this paper, we explain how to compute explicitly the logarithmic singularities of the Green functions of the conformal powers of the Laplacian. These operators include the Yamabe and Paneitz operators, as well as the conformal fractional powers of the Lap…
Prove Riemannian positive mass theorem for asymptotically flat metrics with low-codimension singularities.
problem Prove Riemannian positive mass theorem for asymptotically flat metrics with low-codimension singularities.
method Prove Riemannian positive mass theorem for asymptotically flat metrics with low-codimension singularities.
result Prove Riemannian positive mass theorem for asymptotically flat metrics with low-codimension singularities.
We establish normal forms for conformal vector fields on pseudo-Riemannian manifolds in the neighborhood of a singularity. For real-analytic Lorentzian manifolds, we show that the vector field is analytically linearizable or the manifold is conformally flat. In either case, the vector field is locally conjugate to a no…
Study on solutions near isolated singularities in 6D Yamabe equation.
problem Behavior of solutions near isolated singularities in 6D Yamabe equation.
method Analyze asymptotic behavior of local solutions in non-conformally flat metrics.
result Solutions are asymptotically close to Fowler solutions in 6D.
In this paper we develop an approach to conformal geometry of piecewise flat metrics on manifolds. In particular, we formulate the combinatorial Yamabe problem for piecewise flat metrics. In the case of surfaces, we define the combinatorial Yamabe flow on the space of all piecewise flat metrics associated to a triangul…
The Riemannian Penrose inequality (RPI) bounds from below the ADM mass of asymptotically flat manifolds of nonnegative scalar curvature in terms of the total area of all outermost compact minimal surfaces. The general form of the RPI is currently known for manifolds of dimension up to seven. In the present work, we pro…
We introduce a new kind of Riemannian manifold that includes weakly-, pseudo- and pseudo projective- Ricci symmetric manifolds. The manifold is defined through a generalization of the so called Z tensor; it is named "weakly Z symmetric" and denoted by (WZS)_n. If the Z tensor is singular we give conditions for the exis…
Paper introduces p-Laplace equations for curvature in conformal geometry.
problem Study of geometry and topology of manifolds.
method Introducing p-Laplace equations for intermediate Schouten curvature.
result Nonnegative intermediate Schouten curvature leads to estimates on Hausdorff dimension of singular sets and vanishing of homotopy groups.
Consider an asymptotically flat Riemannian manifold (M,g) of dimension n≥3 with nonempty compact boundary. We recall the harmonic conformal class [g]h of the metric, which consists of all conformal rescalings given by a harmonic function raised to an appropriate power. The geometric significance is that eve…
Paper classifies 3D conformally flat quasi-Para-Sasakian manifolds.
problem Characterizing 3D conformally flat quasi-Para-Sasakian manifolds.
method Provided necessary and sufficient conditions for conformal flatness and characterized manifolds with η=const.
result Characterization of 3D conformally flat quasi-Para-Sasakian manifolds with η=const.
A compact manifold is called Bieberbach if it carries a flat Riemannian metric. Bieberbach manifolds satisfy an isosystolic inequality by a general and fundamental result of M. Gromov. In dimension 3, there exist four classes of non-orientable Bieberbach manifolds up to an affine diffeomorphism. In this paper, We prove…
The study classifies metrics with flat Q-curvature and constant boundary Q-curvature.
problem Classifying metrics with specific curvature properties.
method Developed an approach to separate higher order linear effects from boundary nonlinear effects.
result All such metrics are classified in a conformal class of the unit Euclidean ball.
We generalise the classical Chern-Gauss-Bonnet formula to a class of 4-dimensional manifolds with finitely many conformally flat ends and singular points. This extends results of Chang-Qing-Yang in the smooth case. Under the assumptions of finite total Q curvature and positive scalar curvature at the ends and at the si…
We construct flat metrics in a given conformal class with prescribed singularities of real orders at marked points of a closed real surface. The singularities can be small conical, cylindrical, and large conical with possible translation component. Along these lines we give an elementary proof of the uniformization the…
Paper studies metrics with constant Q-curvature near singular points.
problem Deriving properties of metrics with constant Q-curvature near singularities.
method Refined asymptotic expansion for metrics with constant Q-curvature and scalar curvature.
result Modelled results on similar metrics with scalar curvature, analyzing linearization about Delaunay metrics.
We study a particular class of open manifolds. In the category of Riemannian manifolds these are complete manifolds with cylindrical ends. We give a natural setting for the conformal geometry on such manifolds including an appropriate notion of the cylindrical Yamabe constant/invariant. This leads to a corresponding ve…
Constructs metrics with negative curvature on specific manifold types.
problem Creating negatively curved metrics on locally conformally flat manifolds.
method Using Morse functions to construct conformal metrics.
result Successfully constructs conformal metrics with negative sectional curvature.
The paper explores curvature and flatness in statistical manifolds.
problem Understanding curvature and flatness in statistical manifolds.
method An identity of conformal-projective curvature tensor is studied.
result Relation between curvature constancy and conformal-projective flatness.
Positive projectively flat metrics on Hopf manifolds are locally conformally flat-Kähler.
problem Characterizing projectively flat metrics on Hopf manifolds.
method Partitioning projectively flat metrics into classes based on Chern scalar curvature sign and proving properties of each class.
result Positive projectively flat metrics on Hopf manifolds are locally conformally flat-Kähler.
An almost Einstein manifold satisfies equations which are a slight weakening of the Einstein equations; Einstein metrics, Poincare-Einstein metrics, and compactifications of certain Ricci-flat asymptotically locally Euclidean structures are special cases. The governing equation is a conformally invariant overdetermined…
Compact 3D Cotton-parallel manifolds are always conformally flat.
problem Understanding the properties of compact 3D Cotton-parallel manifolds.
method Analyzing the Cotton tensor and its parallelism condition.
result Compact 3D Cotton-parallel manifolds are conformally flat.
New compact examples of pseudo-Kähler manifolds with essential conformal transformations found.
problem Existence of essential conformal transformations in pseudo-Riemannian manifolds.
method Construction of compact locally conformally pseudo-Kähler manifolds with essential conformal transformations.
result Found compact examples of pseudo-Kähler manifolds with essential conformal transformations that are not conformally flat.
Study prescribed curvature tensor in locally conformally flat manifolds.
problem Solving the Prescribed Curvature Tensor problem in locally conformally flat manifolds.
method Explicit solutions provided for special cases of the tensor R, including complete metrics on Rn.
result Explicit examples of metrics g and conformal metrics g that solve the problem are exhibited.
The paper examines flatness conditions on normal metric contact pairs and proves properties of Einstein manifolds.
problem The study of flatness conditions on normal metric contact pairs.
method Analysis of conformal, concircular, and quasi-conformal curvature tensors.
result Normal metric contact pair manifolds with flat conformal, concircular, and quasi-conformal curvature tensors are Einstein manifolds with specific scalar and sectional curvatures.
We study a fully nonlinear flow for conformal metrics. The long-time existence and the sequential convergence of flow are established for locally conformally flat manifolds. As an application, we solve the $\sk$-Yamabe problem for locally conformal flat manifolds when k=n/2.
Classification of specific pseudo-Riemannian manifolds.
problem Classifying conformally flat generalized Ricci recurrent pseudo-Riemannian manifolds.
method Complete classification through mathematical analysis.
result Conformally flat generalized Ricci recurrent pseudo-Riemannian manifolds are either de Sitter or anti-de Sitter spacetimes.
Study classifies half conformally flat GQE manifolds of signature (2,2).
problem Classifying half conformally flat generalized quasi-Einstein manifolds.
method Analysis and examples provided.
result Natural affine quasi-Einstein equation derived.
Higher-dimensional Ricci flows are shown to have unique and stable solutions.
problem Stability and uniqueness of Ricci flows in higher dimensions.
method Generalization of Bamler-Kleiner's proof to higher dimensions, use of Brendle's classification of κ-solutions, and maximum principle for linearized Ricci-DeTurck flow.
result Canonical evolution through singularities for manifolds with positive isotropic curvature.
It is proved that every locally conformal flat Riemannian manifold all of whose Jacobi operators have constant eigenvalues along every geodesic is with constant principal Ricci curvatures. A local classification (up to an isometry) of locally conformal flat Riemannian manifold with constant Ricci eigenvalues is given i…
Paper connects Dirac operators and automorphic forms on conformally flat manifolds.
problem Understanding the relationship between Dirac operators and automorphic forms.
method Analyzes joint work with John Ryan on conformally flat manifolds.
result Summarizes the connection between Dirac operators and automorphic forms.
The study proves rigidity for Poincaré-Einstein manifolds with flat Euclidean conformal infinity.
problem Proving rigidity for Poincaré-Einstein manifolds with specific conformal infinity.
method Analyzing curvature tensors over level sets of a boundary defining function.
result Rigidity theorem for Poincaré-Einstein manifolds with flat Euclidean conformal infinity.
Nonexistence theorem for product type manifolds, proving no locally conformally flat metrics.
problem Proving nonexistence of locally conformally flat metrics on product manifolds.
method Nonexistence theorem for product type manifolds.
result 4-manifold Σ_g×Σ_h does not admit locally conformally flat metrics for g≥2 and h≥1.
A local classification of the Hermitian manifolds with flat associated connection is given. Hermitian manifolds admitting locally a conformal metric with flat associated connection are characterized by a curvature identity. Locally conformal Kaehler manifolds as well as Hermitian surfaces with vanishing associated conf…
Study of harmonic maps and instantons in 4D.
problem Constructing non-spin, simply-connected Ricci-flat 4-manifolds.
method Non-perturbative approach ruling out conical singularities from axisymmetric harmonic maps.
result Systematic counterexamples to Riemannian black hole uniqueness conjecture.