New theorem shows curvature concentration depends linearly on volume ratio.
problem Gap theorem for nonnegative Ricci curvature manifolds with small curvature concentration.
method Exhibited Ricci flow solution with faster than 1/t curvature decay.
result Curvature concentration depends linearly on asymptotic volume ratio.
New findings on gradient expanding Ricci solitons with finite scalar curvature ratio.
problem Understanding the behavior of gradient expanding Ricci solitons with finite scalar curvature ratio.
method Analyzing complete gradient expanding Ricci solitons with nonnegative Ricci curvature.
result Riemann curvature tensor must have at least sub-quadratic decay for finite asymptotic scalar curvature ratio.
Integral of scalar curvature equals a volume ratio term on certain 3D manifolds.
problem Integral of scalar curvature on manifolds with a pole.
method Asymptotic scaling invariant integral of scalar curvature equals a term determined by asymptotic volume ratio.
result Integral of scalar curvature equals a volume ratio term.
Study curvature and torsion from cross-ratios in discrete curves.
problem Define curvature and torsion for discrete curves using cross-ratios.
method Use Möbius invariant point-insertion-rule to construct circles and express torsion using cross-ratio.
result Discrete curvature and torsion defined using cross-ratios converge to smooth curvature and torsion as sampling density increases.
Study surfaces with constant ratio of principal curvatures in Euclidean and isotropic geometries.
problem Characterize surfaces with constant ratio of principal curvatures in different geometries.
method Differential geometry, line geometry, Lie sphere geometry, ordinary differential equations, algebraic geometry.
result Characterized various types of surfaces like rotational, channel, ruled, helical, and translational.
Sharp volume growth ratio for 3D manifolds with positive scalar curvature.
problem Volume growth and scalar curvature in non-compact Riemannian manifolds.
method Analyzing 3D complete, non-compact manifolds with non-negative Ricci and positive scalar curvature.
result Obtained sharp linear volume growth ratio and rigidity.
The study finds the minimum average area ratio on hyperbolic manifolds and its relation to scalar curvature.
problem Finding the minimum average area ratio on hyperbolic manifolds.
method Analyzing the average area ratio and normalized total scalar curvature for hyperbolic n-manifolds.
result The average area ratio attains a local minimum of 1 at the hyperbolic metric.
In this paper, we study generalized constant ratio (GCR) hypersurfaces in Euclidean spaces. We mainly focus on the hypersurfaces in E4. First, we deal with δ(2)-ideal GCR hypersurfaces. Then, we study on hypersurfaces with constant (first) mean curvature. Finally, we obtain the complete classification of G…
The paper studies curves of constant-ratio in pseudo-Galilean space.
problem Characterizing curves of constant-ratio in pseudo-Galilean space.
method Analyzing spacelike curves with constant-ratio in terms of curvature functions.
result Characterization of special curves of constant-ratio in pseudo-Galilean space.
The main result of this paper is: Given any constant C, there is (ε,k,L) such that if a complete, orientable, noncompact odd-dimensional manifold with bounded positive sectional curvature contains a (ε,k,L)-neck, then the asymptotic scalar curvature ratio is bigger or equal to C. As a application we proved that the…
Sharp Sobolev and Michael-Simon inequalities on curved manifolds.
problem Proving inequalities on manifolds with nonnegative curvature.
method Analyzing asymptotic volume ratio and curvature properties.
result Sharp Sobolev and Michael-Simon inequalities established.
In this paper, we mainly study the mean curvature flow in Kähler surfaces with positive holomorphic sectional curvatures. We prove that if the ratio of the maximum and the minimum of the holomorphic sectional curvatures is less than 2, then there exists a positive constant δ depending on the ratio such that $\cosα\ge…
New pinching estimates control curvature ratios in inverse curvature flows.
problem Controlling curvature ratios in inverse curvature flows.
method Proving pinching estimates for strictly convex hypersurfaces in space forms.
result Smooth convergence of the inverse curvature flow is proven.
Bound on integral of scalar curvature on non-parabolic manifolds.
problem Bounding integral of scalar curvature on non-parabolic manifolds.
method Using monotonicity formulas of Colding and Minicozzi.
result Explicit bound on asymptotic weighted scaling invariant integral of scalar curvature.
We consider convex hypersurfaces for which the ratio of principal curvatures at each point is bounded by a function of the maximum principal curvature with limit 1 at infinity. We prove that the ratio of circumradius to inradius is bounded by a function of the circumradius with limit 1 at zero. We apply this result to …
Minimal surfaces and average area ratio found to be maximized by hyperbolic metrics.
problem Finding sharp relations between minimal surface entropy and average area ratio.
method Ricci flow with surgery and invariant measures.
result Minimal surface entropy maximized by hyperbolic metrics among metrics with scalar curvature ≥ -6.
Local isoperimetric inequality holds for balls with nonpositive curvature.
problem Preserving the isoperimetric ratio in perturbed ball metrics with nonpositive curvature.
method Analyzing perturbations of ball metrics with nonpositive curvature.
result Isoperimetric ratio is preserved only by homotheties of the ball.
Curves in Rn for which the ratios between two consecutive curvatures are constant are characterized by the fact that their tangent indicatrix is a geodesic in a flat torus. For n=3,4, spherical curves of this kind are also studied and compared with intrinsic helices in the sphere.
Paper uses ABP method to prove logarithmic Sobolev inequalities on curved spaces.
problem Proving logarithmic Sobolev inequalities on manifolds with nonnegative curvature.
method Employing the ABP method developed by Brendle.
result Sharp L2 and Lp logarithmic Sobolev inequalities established. Study finds all helical surfaces with a constant ratio of principal curvatures.
problem Identifying helical surfaces with a constant ratio of principal curvatures.
method Employing the contours for parallel projection orthogonal to the helical axis, and solving an ordinary differential equation.
result Explicit CRPC surfaces beyond rotational ones are determined.
The study finds parametrizations for surfaces of revolution with a linear curvature ratio.
problem Deriving surfaces of revolution with a specific curvature ratio.
method Derives parametrizations for surfaces of revolution with an affine-linear relation between their curvature radii.
result Explicit parametrizations found for a countably-infinite number of surfaces.
On a closed weighted Riemannian manifold with nonnegative Bakry-Émery Ricci curvature, it is shown that the ratio of the k-th to first eigenvalues of the weighted Laplacian is dominated by 641k2, using an argument via the Cheeger constant. While improving the previous exponential upper bound, the order of k here…
We use generalised cross--ratios to prove the Ptolemaean inequality and the Theorem of Ptolemaeus in the setting of the boundary of symmetric Riemannian spaces of rank 1 and of negative curvature.
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.
Geodesic flows on surfaces have specific fractional-linear integrals related to constant cross-ratios.
problem Characterizing geodesic flows on surfaces with fractional-linear integrals.
method Proving the dimension of fractional-linear integrals and giving a geometric criterion.
result The dimension of fractional-linear integrals is either 3 or 5, corresponding to constant curvature.
The paper estimates curvature for specific 4D Ricci solitons.
problem Estimating curvature for 4D complete gradient expanding Ricci solitons.
method Deriving bounds on curvature and its derivatives for solitons with nonnegative Ricci curvature.
result Curvature and its derivatives are bounded by scalar curvature for these solitons.
The study examines the geometry of Q-curvature and its associated functions.
problem Investigating the properties of Q-curvature and its associated functions. method Analyzing a complete and conformal metric g=e2u∣dx∣2 on Rn with non-negative nth-order Q-curvature and non-negative scalar curvature. result The growth rate of kth elementary symmetric function of Ricci curvature over geodesic ball of radius r is at most polynomial in r with order n−2k for all 1≤k≤2n−2. The paper proves isoperimetric inequalities in manifolds with small negative Ricci curvature.
problem Proving isoperimetric inequalities in manifolds with small negative Ricci curvature.
method Expanding on the ABP method, the paper uses the elliptic Kato constant to control the non-negativity of the Ricci-tensor and applies techniques from Li-Tam and Kasue.
result Sharp isoperimetric inequalities in the limit are proven in the presence of small negative curvature.
Study existence and uniqueness of solutions for Yamabe problem on non-compact manifolds with negative curvature.
problem Existence and uniqueness of solutions for the Yamabe problem on non-compact manifolds of negative curvature type.
method Used partial C2 decay of the metric and local volume ratio condition to establish existence and uniqueness results. result Established existence and uniqueness results for the Yamabe problem on non-compact manifolds of negative curvature type.
The paper proves rigidity and ε-regularity theorems for Ricci shrinkers.
problem Understanding the structure and behavior of Ricci shrinkers.
method Proving rigidity and ε-regularity theorems for Ricci shrinkers using entropy and curvature.
result Non-compact Ricci shrinkers are asymptotic to cones under certain curvature conditions.
Estimates on Einstein manifolds improve Brownian motion behavior and curvature limits.
problem Improving estimates on Einstein manifolds for Brownian motion behavior.
method Generalizing Benjamini-Pemantle-Peres estimate to manifolds with Ricci curvature bounds.
result Sharp estimates for Brownian motion on high curvature parts of Ricci-flat manifolds.
The paper proves inequalities for closed surfaces involving mean curvature.
problem Proving geometric inequalities for closed surfaces in Euclidean space.
method Verification of inequalities for convex surfaces and addressing Topping's conjecture.
result Optimal scaling law between Willmore energy and isoperimetric ratio for convex surfaces.
We study the geometry at infinity of expanding gradient Ricci solitons of dimension greater than two with finite asymptotic curvature ratio without curvature sign assumptions. We mainly prove that they have a cone structure at infinity.
Many classical objects on a surface S can be interpreted as cross-ratio functions on the circle at infinity of the universal covering. This includes closed curves considered up to homotopy, metrics of negative curvature considered up to isotopy and, in the case of interest here, tangent vectors to the Teichmüller space…
A twisted curve in Euclidean 3-space E^3 can be considered as a curve whose position vector can be written as linear combination of its Frenet vectors. In the present study we study the twisted curves of constant ratio in E^3 and characterize such curves in terms of their curvature functions. Further, we obtain some re…
We prove that compact Kähler manifolds whose sectional curvatures are close to 1/4-pinched have ratios of Chern numbers close to the corresponding ratios of a complex hyperbolic space form. We deduce that the Mostow-Siu surfaces (and their three-dimensional analogues constructed by the first author) do not admit Kähler…
Complete Ricci flow from singular 3D manifold with pseudolocality.
problem Constructing complete Ricci flow from singular 3D manifold.
method Combining pseudolocality results for singular and nonsingular flows.
result Ricci flow is complete for positive times under certain conditions.
Study of 3D steady gradient Ricci solitons using level set flow.
problem Characterizing the behavior of level sets in 3D steady gradient Ricci solitons.
method Analysis of scalar curvature and umbilical ratio using level set flow.
result The umbilical ratio of level sets is bounded by specific functions of the scalar curvature.
Closed loop solitons in a plane, whose curvatures obey the modified Korteweg-de Vries equation, were investigated. It was shown that their tangential vectors are expressed by ratio of Weierstrass sigma functions for genus one case and ratio of Baker's sigma functions for the genus two case. This study is closely relate…
An ODE variational calculation shows that an image principle curvature ratio factor can raise the lower bound, 2(Image Area), on energy of a harmonic map of a surface into Rn. In certain situations, including all radially symmetry harmonic maps, equality is achieved.
We show that the scalar curvature of a steady gradient Ricci soliton satisfying that the ratio between the square norm of the Ricci tensor and the square of the scalar curvature is bounded by one half, is boundend from below by the hyperbolic secant of one half the distance function from a fixed point.
We analyze a gradient flow of closed planar curves minimizing the anisoperimetric ratio. For such a flow the normal velocity is a function of the anisotropic curvature and it also depends on the total interfacial energy and enclosed area of the curve. In contrast to the gradient flow for the isoperimetric ratio, we sho…
Study bond market making with hit-ratio target using optimal control and HJB equations.
problem Optimizing bond market making with hit-ratio target in OTC markets.
method Stochastic optimal control approach, dualizing hit-ratio target, HJB equation, Riccati equation, linearization.
result Explicit quote decompositions into riskless spread, inventory-risk correction, and hit-ratio correction.
We give upper and lower bounds for the ratio of the volume of metric ball to the area of the metric sphere in Finsler-Hadamard manifolds with pinched S-curvature. We apply these estimates to find the limit at the infinity for this ratio. Derived estimates are the generalization of the well-known result in Riemannian ge…
New method identifies unique group actions on CAT(0) cube complexes.
problem Identifying group actions on CAT(0) cube complexes.
method Developed cross-ratio on Roller boundaries and extended cross-ratio preserving maps.
result Group actions on irreducible CAT(0) cube complexes are uniquely determined by their length function.
Paper improves greedy algorithm for non-submodular matroid constraints.
problem Maximizing non-submodular functions subject to matroid constraints.
method Developed and analyzed a greedy algorithm with approximation guarantees.
result Greedy algorithm offers approximation factors for matroid constraints.
This research solves Plateau's problem for CRPC surfaces.
problem Constructing surfaces with constant ratio of principal curvatures.
method Proposed a family of surfaces containing a given minimal surface without flat points.
result Obtained a partial solution to Plateau's problem for CRPC surfaces.
The study bounds harmonic functions on manifolds with nonnegative Ricci curvature.
problem Bounding harmonic functions on manifolds with specific curvature properties.
method Analyzing the asymptotic volume ratio and eigenvalue counting function.
result Sharp upper bounds for harmonic functions with polynomial growth.