This note is a study of nonnegativity conditions on curvature which are preserved by the Ricci flow. We focus on specific kinds of curvature conditions which we call noncoercive, these are the conditions for which nonnegative curvature and vanishing scalar curvature doesn't imply flatness. We show that, in dimensions g…
Smooths metrics with nonnegative scalar curvature near singular sets.
problem Approximating metrics with nonnegative scalar curvature near singularities.
method Ricci-DeTurck flow to approximate metrics.
result Approximated metrics converge to the original metric in C∞ away from the singular set. Study connects isoperimetric sets, mass concepts, and nonnegative scalar curvature.
problem Understanding mass concepts in nonnegative scalar curvature manifolds.
method Review and analysis of isoperimetric sets and their role in mass concepts.
result Equivalence among mass concepts holds for isoperimetric sets with connected boundaries.
Survey of nonnegative scalar curvature sequences and their limits.
problem Understanding sequences of manifolds with nonnegative scalar curvature.
method Analyzing sequences of manifolds with nonnegative scalar curvature and proving convergence.
result Proved the GH and SWIF convergence of an extreme example.
The paper proves rigidity results for manifolds with nonnegative scalar curvature.
problem Rigidity of manifolds with nonnegative scalar curvature.
method New proof and tricks to establish compactness and rigidity results.
result Optimal 2-systole inequality and rigidity results for manifolds with positive scalar curvature.
Paper proves mass theorems for nonnegative scalar curvature metrics.
problem Proving mass theorems for metrics with nonnegative scalar curvature.
method New local inverse mean curvature flow with quantitative stability.
result Existence of isoperimetric sets in low regularity metrics.
Study compact sequences of warped product circles over spheres with nonnegative scalar curvature.
problem Compactness of sequences of warped product circles over spheres with nonnegative scalar curvature.
method Proved subsequence convergence to a W1,p Riemannian metric for all p<2 with nonnegative scalar curvature in the distributional sense. result Proved compactness of sequences of warped product circles over spheres with nonnegative scalar curvature.
Simplified Obata-Vétois argument for Einstein manifolds with nonnegative scalar curvature.
problem Identifying conditions for closed conformally Einstein manifolds to be Einstein.
method Simplified Obata-Vétois argument, identifying a closed interval containing zero.
result Closed conformally Einstein manifolds with nonnegative scalar curvature are Einstein if they satisfy certain conditions.
Paper studies convergence of nonnegative scalar curvature metrics to a specific limit space.
problem Understanding convergence of nonnegative scalar curvature metrics.
method Analyzes a sequence of warped product metrics on $\Sph^2 imes \Sph^1$.
result Sequence converges to an extreme limit space in specific senses.
In this note, we consider the isoperimetric inequality on an asymptotically flat manifold with nonnegative scalar curvature, and improve it by using Hawking mass. We also obtain a rigidity result when equality holds for the classical isoperimetric inequality on an asymptotically flat manifold with nonnegative scalar cu…
Study finds conditions for minimal surfaces in noncompact spaces.
problem Existence of minimal surfaces in noncompact spaces with nonnegative scalar curvature.
method Conditions on a 2-sphere and its boundary.
result Existence of a closed minimal surface homologous to the boundary.
New theorem links quaternionic-Kähler manifolds to symmetric spaces.
problem Understanding curvature properties of quaternionic-Kähler manifolds.
method Analyzing positive scalar curvature and nonnegative sectional curvature.
result Compact quaternionic-Kähler manifolds with these properties are symmetric.
Study shows no large mean curvature fill-ins for nonnegative scalar curvature.
problem Existence of fill-ins with nonnegative scalar curvature and large mean curvature.
method Analyzes closed Riemannian manifolds and scalar curvature properties.
result No closed Riemannian manifold admits a fill-in with nonnegative scalar curvature and large mean curvature.
Study on 3-manifolds with nonnegative scalar curvature and positive harmonic functions.
problem Characterizing 3-manifolds with nonnegative scalar curvature.
method Exhaustions by level sets of harmonic functions and refined average gradient estimates.
result Contractible 3-manifolds are diffeomorphic to R^3, and handlebodies have genus at most 1.
Study on harmonic functions on nonnegative curvature 3D manifolds.
problem Analyzing harmonic functions on specific 3D manifolds.
method Inspired by Miao, developed a monotonic quantity for level sets of harmonic functions on (R3∖{0},g) with nonnegative scalar curvature. result Established a rigidity result for the derived monotonic quantity.
Proves Calabi-Yau theorem for certain nonnegative curvature manifolds.
problem Proving a Calabi-Yau type theorem for specific manifolds.
method Existence result for bounded regions with weakly mean-concave boundary.
result Proves contractibility of certain manifolds with positive scalar curvature.
We show that closed hypersurfaces in Euclidean space with nonnegative scalar curvature are weakly mean convex. In contrast, the statement is no longer true if the scalar curvature is replaced by the k-th mean curvature, for k greater than 2, as we construct the counter-examples for all k greater than 2. Our proof relie…
This paper classifies complete self-shrinkers in R^(n+1) with nonnegative constant scalar curvature.
problem Classifying self-shrinkers with specific curvature conditions.
method Analyzing the mean curvature flow and using geometric properties.
result Complete classifications of n-dimensional self-shrinkers in R^(n+1) with nonnegative constant scalar curvature.
Gromov and Sormani conjectured that sequences of compact Riemannian manifolds with nonnegative scalar curvature and area of minimal surfaces bounded below should have subsequences which converge in the intrinsic flat sense to limit spaces which have nonnegative generalized scalar curvature and Euclidean tangent cones a…
Theorem proves minimal hypersurfaces in nonnegative scalar curvature manifolds are smooth.
problem Minimal hypersurfaces with singularities in manifolds of nonnegative scalar curvature.
method Singularity removal rigidity theorems, spectral PMT for AF manifolds.
result Smoothness of minimal hypersurfaces in nonnegative scalar curvature manifolds.
The paper derives inequalities for p-capacitary functions in 3-manifolds with nonnegative scalar curvature.
problem Deriving inequalities for p-capacitary functions in 3-manifolds with nonnegative scalar curvature. method Deriving general monotone quantities and geometric inequalities associated with p-capacitary functions in asymptotically flat 3-manifolds with nonnegative scalar curvature. result The inequalities become equalities on the spatial Schwarzschild manifolds outside rotationally symmetric spheres.
New findings extend rigidity results to broader classes of manifolds.
problem Extending rigidity results to non-warped product spaces.
method Establishing rigidity theorems for manifolds conformal to those with nonnegative curvature.
result New families of manifolds exhibit scalar-mean rigidity.
New theorem on 3-manifolds with curvature and convex boundary.
problem Understanding 3-manifolds with specific curvature and boundary properties.
method Analyzes properties of Riemannian 3-manifolds with nonnegative scalar curvature and mean-convex boundary.
result Shows flatness of certain 3-manifolds containing specific geometric objects.
Paper proves convergence of warped product manifolds to a nonnegative scalar curvature limit.
problem Proving convergence of sequences of manifolds with nonnegative scalar curvature.
method Warped product manifolds with diverging circular fibers, proving convergence in W1,p sense. result Sequence converges to an extreme limit space with nonnegative scalar curvature.
Derive monotone quantities for harmonic functions on asymptotically flat 3-manifolds with nonnegative scalar curvature.
problem Derive monotone quantities for harmonic functions on asymptotically flat 3-manifolds with nonnegative scalar curvature.
method Follow the strategy developed in Miao.
result Derive monotone quantities for harmonic functions on asymptotically flat 3-manifolds with nonnegative scalar curvature.
4-manifolds with nonnegative sectional curvature are area-extremal.
problem Finding extremal properties of 4-manifolds with curvature constraints.
method Analyzing sections in the kernel of a twisted Dirac operator and using the Finsler--Thorpe trick.
result Large classes of compact 4-manifolds are area-extremal.
Study area-minimizing hypersurfaces in singular manifolds with nonnegative scalar curvature.
problem Characterize singularities of area-minimizing hypersurfaces in singular ambient manifolds.
method Analyze tangent cones with nonnegative scalar curvature and prove codimension bounds.
result Singular set has codimension at least 3, with an example showing sharpness.
Study proves inequalities for mass-capacity on curved spaces.
problem Proving nonnegativity and positive lower bounds of mass on curved spaces.
method Applying mass-capacity inequalities from \cite{M22} to manifolds with nonnegative scalar curvature.
result Sufficient conditions for nonnegativity and positive lower bounds of mass.
The study finds a limit on the volume growth of certain 3-manifolds.
problem Volume growth of noncompact 3-manifolds with specific curvature properties.
method Analyzes 3-dimensional complete non-compact Riemannian manifolds with asymptotically nonnegative Ricci curvature and positive scalar curvature.
result Optimal asymptotic volume ratio for manifolds with finite first Betti number and linear volume growth.
We explore to what extent one may hope to preserve geometric properties of three dimensional manifolds with lower scalar curvature bounds under Gromov-Hausdorff and Intrinsic Flat limits. We introduce a new construction, called sewing, of three dimensional manifolds that preserves positive scalar curvature. We then use…
The paper studies 3D manifolds with positive scalar curvature and volume growth.
problem Understanding the geometry of 3D manifolds with positive scalar curvature.
method Analyzes volume and geometric properties of 3D complete manifolds with positive scalar curvature, considering different curvature conditions.
result Volume growth estimates for 3D manifolds with positive scalar curvature, answering Gromov's question affirmatively.
In this paper we investigate complete critical metrics of the L2-norm of the scalar curvature. We prove that any complete critical metric with positive scalar curvature has constant scalar curvature and we characterize critical metrics with nonnegative scalar curvature in dimension three and four.
Estimates scalar curvature without nonnegativity, showing gap phenomenon on manifolds.
problem Estimating scalar curvature without curvature nonnegativity assumption.
method Derive estimates for scalar curvature and mean curvature on manifolds and domains.
result Show that metrics on even dimensional manifolds with nonzero Euler characteristic are ε-gap distance extremal.
The paper studies nonlinear mass concepts in 3-manifolds with nonnegative scalar curvature.
problem Nonlinear isocapacitary mass in 3-manifolds with nonnegative scalar curvature.
method Derives positive mass theorems and shows mass coincides with ADM mass under mild conditions.
result Nonlinear masses coincide with ADM mass and prove the Penrose inequality.
The study restricts scalar curvature on certain noncompact manifolds.
problem Ruling out complete metrics with nonnegative scalar curvature.
method Conditions and examples of positive scalar curvature metrics.
result Examples of manifolds with positive scalar curvature.
Study of manifolds with specific curvature properties using capillary surfaces.
problem Obtaining geometric properties of manifolds with nonnegative scalar curvature and strictly mean convex boundary.
method Use of stable capillary surfaces and Urysohn width to study geometric properties.
result Obtained an obstruction to filling 2-manifolds by 3-manifolds.
Motivated by the quasi-local mass problem in general relativity, we apply the asymptotically flat extensions, constructed by Shi and Tam in the proof of the positivity of the Brown--York mass, to study a fill-in problem of realizing geometric data on a 2-sphere as the boundary of a compact 3-manifold of nonnegative sca…
Study proves curvature flow existence on CR manifolds.
problem Existence of curvature flow solutions on CR manifolds.
method Prescribed Webster scalar curvature flow approach.
result Proves existence of curvature flow solutions on 3D CR manifolds.
In this paper, we study the boundary behaviors of compact manifolds with nonnegative scalar curvature and with nonempty boundary. Using a general version of Positive Mass Theorem of Schoen-Yau and Witten, we prove the following theorem: For any compact manifold with boundary and nonnegative scalar curvature, if it is s…
The paper proves inequalities for scalar curvature on various manifolds.
problem Proving inequalities for scalar curvature on different types of manifolds.
method Analyzing Riemannian manifolds with nonnegative Ricci curvature and applying Cohn-Vossen-type inequalities.
result Sharp asymptotic scalar-curvature flux upper bound of 8π in dimension three.
Estimates Bartnik mass for metrics with nonnegative Gauss curvature.
problem Estimating Bartnik mass for specific metric configurations.
method Using area, total mean curvature, and a metric roundness measure.
result Estimate approaches sharp value for round spheres.
We construct a compact Kähler manifold of nonnegative quadratic bisectional curvature, which does not admit any Kähler metric of nonnegative orthogonal bisectional curvature. The manifold is a 7-dimensional Kähler C-space with second Betti number equal to 1, and its canonical metric is a Kähler-Einstein metric of posit…
Improved mass-capacity bounds for specific 3D manifolds.
problem Sharp mass-capacity inequality and upper bounds for 3D asymptotically flat manifolds.
method Monotonicity formulas associated with a harmonic potential.
result Improved bounds on ADM mass and capacity in terms of boundary area.
Sharp bound on scalar curvature integral in 3-manifolds.
problem Bounding the integral of scalar curvature on 3-manifolds.
method Geodesic ball analysis with nonnegative Ricci curvature.
result Integral of scalar curvature is bounded by 8πR for large radii. Uniformly Euclidean metrics with isolated singularities on certain manifolds are Ricci flat and have nonnegative synthetic Ricci curvature.
problem Proving the existence of Ricci flat metrics with isolated singularities on specific manifolds.
method Demonstrating nonnegative synthetic Ricci curvature using the RCD(0, n) condition.
result Uniformly Euclidean metrics with isolated singularities on Mn=Tn#M0 are Ricci flat and extend smoothly over the singularity. New manifolds with negative curvature limit to one with negative curvature.
problem Preserving nonnegative scalar curvature under intrinsic flat convergence.
method Constructing sequences of manifolds with positive scalar curvature.
result Intrinsic flat limit of manifolds with negative scalar curvature.
The following version of a conjecture of Fischer-Colbrie and Schoen is proved: If M is a complete Riemannian 3-manifold with nonnegative scalar curvature which contains a two-sided torus S which is of least area in its isotopy class then M is flat. This follows from a local version derived in the paper.
The paper establishes distance estimates for manifolds with lower scalar curvature bounds.
problem Distance estimates on manifolds with lower scalar curvature bounds.
method Introduced a definition of relative index via a deformed Dirac operator trick and proved index coincidence with Callias operators.
result Proved short neck inequality and quantitative shielding result with positive scalar curvature.