The study proves the existence of geodesics on reversible Finsler spheres.
problem Existence of closed geodesics on Finsler 2-spheres.
method Generalization of Grayson's curve shortening flow.
result Existence of three simple closed geodesics and infinitely many closed geodesics.
New measure proves Poncelet-type theorems.
problem Proving Poncelet-type theorems.
method Introducing a new invariant measure on the circle.
result Simple proof of Emch closing theorem.
Paper generalizes CR Obata theorem to weighted Sasakian manifolds.
problem Deriving eigenvalue estimates for weighted Kohn Laplacian.
method Derived weighted CR Reilly's formula and applied to Sasakian manifolds.
result CR Obata theorem proven for weighted Sasakian manifolds.
Study extends surface embedding theorems to non-orientable cases.
problem Embedding non-orientable surfaces in 4-manifolds.
method Conditions for embedding non-orientable surfaces as sums of surfaces and projective planes.
result Extends Gabai and Auckly-Kim-Melvin-Ruberman-Schwartz theorems to non-orientable surfaces.
Proof confirms central limit theorem for geodesics on hyperbolic surfaces.
problem Understanding the distribution of geodesic lengths on hyperbolic surfaces.
method Proving a central limit theorem for geodesic lengths.
result The Chas-Li-Maskit conjecture is proven for hyperbolic pair of pants.
New theorem on geodesics on non-compact manifolds.
problem Existence of geodesics with specific properties.
method Analyzing geodesics with local homology in maximal degree.
result Infinitely many closed geodesics on non-compact manifolds.
In this paper we examine different aspects of the geometry of closed conformal vector fields on Riemannian manifolds. We begin by getting obstructions to the existence of closed conformal and nonparallel vector fields on complete manifolds with nonpositive Ricci curvature, thus generalizing a theorem of T. K. Pan. Then…
The Borsuk-Ulam theorem is applied to 3-manifolds with Nil geometry.
problem Determining involutions on 3-manifolds with Nil geometry.
method Applying the Borsuk-Ulam theorem to closed, connected 3-manifolds with Nil geometry.
result All free involutions on the 3-manifolds and their Borsuk-Ulam index are determined.
Proves a pinching theorem for self-shrinkers of mean curvature flow.
problem Pinch on the squared norm of the second fundamental form of self-shrinkers.
method Proves a theorem for n−dimensional closed self-shrinkers. result Closed self-shrinkers must be the standard sphere if pinched.
The paper studies hyperbolic phenomena on closed surfaces using bicorn curves.
problem Understanding hyperbolic phenomena on curve graphs of closed surfaces.
method Using the theory of bicorn curves to analyze the curve graphs of closed surfaces.
result Proves that the curve graph of any closed surface is 15-hyperbolic with one exception.
Sphere theorems for p-Laplacian eigenvalues established.
problem Sphere theorems for p-Laplacian eigenvalues.
method Established sphere theorems for p-Laplacian eigenvalues.
result Sphere theorems for p-Laplacian eigenvalues established.
Geometric invariant theory for real Lie groups proved.
problem Closed orbits and null cone stratification in real reductive Lie groups.
method Completely self-contained proof focusing on geometric and analytic methods.
result Applies to non-rational linear actions.
Simplified proof of Cerf's theorem on 3-sphere diffeomorphisms.
problem Proving the connectedness of direct diffeomorphisms of the 3-sphere.
method Rigidity property of foliations defined by non-vanishing closed one-forms.
result Connected group of direct diffeomorphisms of the 3-sphere.
Study classifies manifolds with nonpositive curvature and finds conformal Killing forms.
problem Characterizing manifolds with nonpositive curvature operator.
method Classification and vanishing theorems for conformal Killing forms.
result Classification and vanishing results for conformal Killing forms.
It is showed that on a plane with a radial density the Four Vertex Theorem holds for the class of all simple closed curves if and only if the density is constant. But for the class of simple closed curves that are invariant under a rotation about the origin, the Four Vertex Theorem holds for every radial density.
The study classifies spaces with specific conformal vector fields.
problem Characterizing closed vacuum static spaces with non-Killing conformal vector fields.
method Provided characterizations and established an identity involving the characteristic function.
result Derived a rigidity theorem and classified spaces with the vector field.
We prove Wadsley's theorem for foliations by closed non-lightlike geodesics. As an application we show that every pseudo-Riemannian and non-Riemannian 2-mainfold, all of whose time- or spacelike geodesics are closed, is diffeomorphic to S1×R. Further we show that every pseudo-Riemannian 2-manifold with index …
Local gap theorem for Ricci shrinkers ensures flatness if certain functionals are close to zero.
problem Understanding the global geometry of Ricci shrinkers from local information.
method Proving a local gap theorem using the local μ-functional. result Ricci shrinkers are flat if the local μ-functional is close to zero. Study open 3-manifolds as sums of closed ones, finding a classification.
problem Classifying open 3-manifolds that are sums of closed 3-manifolds.
method Introduced topological invariants, classified when finitely many summands up to diffeomorphism.
result Unified classification of open 3-manifolds and closed 3-manifolds.
Kahn and Markovic \cite{KahnMark} proved that the fundamental group of each closed hyperbolic three manifold contains a closed surface subgroup. One of the main ingredients in their proof is a theorem which states that an assignment of nearly real, complex Fenchel-Nielsen coordinates to the cuffs of a pants decompositi…
The paper generalizes Fenchel's theorem for curves with singularities.
problem Proving a generalized Fenchel's theorem for closed curves with singularities.
method Generalization of Fenchel's theorem for closed frontal curves in Euclidean space.
result Total absolute curvature of non-co-orientable closed frontal curves is at least π, with equality conditions.
We review and simplify the slice theorem for Riemannian metrics.
problem Existence of slices for Riemannian metrics.
method Review and concise proof of the slice theorem.
result More concise proof of slice existence.
Given a normed plane P, we call P-cycloids the planar curves which are homothetic to their double P-evolutes. It turns out that the radius of curvature and the support function of a P-cycloid satisfy a differential equation of Sturm-Liouville type. By studying this equati…
New findings on mesh group-planes validate Signature-inverse Theorem under specific conditions.
problem Invalidity of existing inverse theorems for mesh group-planes.
method Classification of three and five point meshes, analysis of joint invariant signatures.
result Valid conditions for the Signature-inverse Theorem in mesh group-planes.
In this work we consider a question in the calculus of variations motivated by riemannian geometry, the isoperimetric problem. We show that solutions to the isoperimetric problem, close in the flat norm to a smooth submanifold, are themselves smooth and C2,α-close to the given sub manifold. We show also a version …
The paper proves a theorem for generalized p-Kähler manifolds.
problem Characterization of compact generalized p-Kähler manifolds.
method Proof based on duality between closed and exact positive forms and currents.
result Complete unified proof of Characterization Theorem for compact generalized p-Kähler manifolds.
New theorem shows shapes close to balls, flow converges to balls in 2D and 3D.
problem Understanding the asymptotic behavior of volume-preserving mean curvature flow.
method Proved a new quantitative Alexandrov theorem and used it to show flow convergence.
result Weak solutions of volume-preserving mean curvature flow converge to disjoint balls in R^2 and R^3.
The study proves the existence of many geodesics on complex manifolds.
problem Existence of closed geodesics on manifolds with non-trivial first Betti number.
method Combining Mañé's theorem with a new theorem about minimal geodesics and transverse homoclinic points.
result Proves the existence of infinitely many closed geodesics of arbitrary large length on manifolds with non-trivial first Betti number.
Compact theorem for minimal surfaces with lower injectivity radius.
problem Proving compactness of minimal surfaces with lower injectivity radius.
method Variant of Choi--Schoen compactness theorem, focusing on injectivity radius.
result Proved compactness theorem for minimal surfaces.
In this paper, we establish a Gauss-Bonnet-Chern theorem for general closed complex Finsler manifolds.
An exotic plane exists in an acylindrical 3-manifold without being closed.
problem Does a geodesic plane in an acylindrical 3-manifold remain closed or dense?
method Explicit construction and analysis of a specific example.
result An example of a geodesic plane that is closed in the interior but not in the manifold itself.
The paper extends an Alexandrov theorem to Minkowski spacetime.
problem Generalizing Alexandrov's theorem to Minkowski spacetime.
method Adapting conditions for closed codimension-two spacelike submanifolds in Minkowski spacetime.
result A generalized Alexandrov theorem for Minkowski spacetime.
In this paper, we prove W1,p (p>n) and C0,α (0<α<1) precompactness for classes of Riemannian n-manifolds with boundary satisfying uniform L∞ bounds on curvature, mean curvature, diameter, and the (n−1)-volume of the boundary. In particular, we identify a class of convex manifolds and a cl…
Obstructions found for closed Fedosov star products on symplectic and Kähler manifolds.
problem Existence of closed Fedosov star products on symplectic and Kähler manifolds.
method Normalized trace of Fedosov star product, cohomology classes, and formal 2-forms.
result Integral invariants attached to symplectic and Kähler manifolds as obstructions to closed Fedosov star products.
Sphere theorems for specific manifolds with curvature constraints.
problem Sphere theorems for Riemannian manifolds with scalar curvature bounds and non-collapsed RCD(n−1,n) spaces. method Analysis of scalar curvature and mean distance constraints.
result Established sphere theorems for the specified manifolds.
The paper extends the collar theorem to non-compact surfaces using new comparison theorems.
problem Proving the collar theorem for non-compact surfaces.
method Developed new Toponogov-type triangle comparison theorems.
result Eliminated the compactness hypothesis for the collar theorem.
Proves convexity of certain hypersurfaces with negative λ.
problem Understanding convexity of hypersurfaces with specific λ values.
method Analyzes mean convex hypersurfaces and proves convexity for λ ≤ 0.
result Closed n-dimensional mean convex λ-hypersurfaces are convex if λ≤0. Computes invariant for smooth h-cobordisms families, proving duality and vanishing theorems.
problem Computing invariants for smooth h-cobordisms families.
method Using Dwyer, Weiss, and Williams work, fiberwise generalized Morse function, fiberwise Poincaré--Hopf theory.
result Duality theorem for smooth structure class, vanishing theorem for Rigidity Conjecture.
Two main theorems are proved in this paper. Theorem 1: There is a constant C(n, D) depending only on n and D such that for a closed Riemannian n-manifold satisfying Ric > -(n-1) and Diam < D, the ith bounded Betti number is bounded by C(n, D). Here the ith bounded Betti number is defined as the dimension of the image o…
In this article we give a totally new proof of the integral localization formula for equivariantly closed differential forms (Theorem 7.11 in [BGV]). We restate it here as Theorem 2. This localization formula is very well known, but the author hopes to adapt this proof to obtain a more general result in the future.
The article studies cohomology on complex manifolds and proves vanishing theorems.
problem Investigating topological properties of complex manifolds.
method Using Dolbeault-Morse-Novikov cohomology and integral inequalities.
result The Hirzebruch χ_y-genus vanishes on certain complex manifolds.
In this article, we give a theorem of reduction of the structure group of a principal bundle P with regular structure group G. Then, when G is in the classes of Lie groups defined by T.Robart [13], we define the closed holonomy group of a connection as the minimal closed Lie subgroup of G for which the previous theorem…
The paper proves existence of multiple closed CMC hypersurfaces with small mean curvature.
problem Existence of multiple closed CMC hypersurfaces with small mean curvature.
method Analyzes a closed Riemannian manifold to prove the existence of multiple closed CMC hypersurfaces with optimal regularity.
result For all m∈N, there exists c∗(m)>0 such that if 0<c<c∗(m), (M,g) contains at least m many closed c-CMC hypersurfaces with optimal regularity. Paper proves rigidity theorems for geodesically reversible Finsler metrics.
problem Understanding geodesically reversible Finsler metrics in closed manifolds.
method Applied theory of volumes and areas on Finsler spaces to establish rigidity theorems.
result Partial explanation of the scarcity of geodesically reversible Finsler metrics in closed manifolds.
Theorem converse to Jordan's curve theorem says that {\it if a compact set K has two complementary domains in R2, from each of which it is at every point accessible, it is a simple closed curve}. We show that the requirement of this theorem that {\it all} points of K were accessible from {\it both} complementa…
The famous Uniformization Theorem states that on closed Riemannian surfaces there always exists a metric of constant curvature for the Levi-Cevita connection. In this article we prove that an analogue of the uniformization theorem also holds for connections with metric torsion in the case of non-positive Euler characte…
In his book (II.5), Connes gives a proof of the Atiyah-Singer index theorem for closed manifolds by using deformation groupoids and appropiate actions of these on R^N. Following these ideas, we prove an index theorem for manifolds with boundary.
Compactness theorem for quasiregular maps between manifolds.
problem Compactness of sequences of quasiregular mappings.
method Gromov's compactness theorem for pseudoholomorphic curves.
result Subsequence of quasiregular mappings converges to a quasiregular map on a nodal manifold.