We determine the Hausdorff limit-set of the Euclidean hypersurfaces with large λ1 or small extrinsic radius. The result depends on the Lp norm of the curvature that is assumed to be bounded a priori, with a critical behaviour for p equal to the dimension minus 1.
In this paper we consider a class of weighted-volume preserving curvature flows acting on hypersurfaces that are trapped within two parallel hyperplanes and satisfy an orthogonal boundary condition. In the author's thesis the stability of cylinders under the flows was considered; it was found that they are stable provi…
Critical spherical catenoids have Robin nullity and asymptotic radius determined.
problem Analyzing the critical spherical catenoids in hyperbolic space.
method Analytic results using Sturm-Liouville theory, Beta-function evaluation, and Laplace asymptotic analysis.
result Robin nullity and asymptotic radius of the critical spherical catenoid are determined.
Study lower bounds for connectivity of distance function level sets in convex sets.
problem Understanding connectivity of distance function level sets in convex sets.
method Lower bound calculation using critical points of the distance function.
result Provide a lower bound for the range of connectivity.
In this paper we investigate the properties of small surfaces of Willmore type in Riemannian manifolds. By \emph{small} surfaces we mean topological spheres contained in a geodesic ball of small enough radius. In particular, we show that if there exist such surfaces with positive mean curvature in the geodesic ball $B_…
The paper simplifies complex 2D functions near their critical points.
problem Simplifying smooth functions on 2-manifolds near critical points.
method Explicit construction of coordinate changes to canonical form.
result Estimates the radius of required neighbourhoods for specific singularity types.
We study critical Riemannian 4-manifolds with a lower bound on Ricci curvature, but no a priori analytic constraints such as on Sobolev constants. We derive elliptic-type estimates for the local curvature radius, which itself controls sectional curvature. The primary method is construction of blow-ups of degenerating m…
Study on critical faces convergence in a Poisson point process.
problem Convergence of point processes associated with critical faces in a Čech filtration.
method Established convergence in M0-topology for critical faces above vanishing threshold. result Obtained limit theorems for positive and negative critical faces.
Random subgroups in hyperbolic spaces have full limit sets and bounded critical exponents.
problem Understanding stationary random subgroups in hyperbolic spaces.
method Analyzing limit sets and critical exponents of random subgroups.
result Random subgroups have full limit sets and bounded critical exponents.
In this paper we consider the uniqueness problem of the constant mean curvature spheres in asymptotically flat 3-manifolds. We require the metric have the form g_{ij}=δ_{ij}+h_{ij} with h_{ij}=O_{4}(r^{-1}) and R=O(r^{-3-τ}),τ>0. We do not require the metric to be close to Schwarzschild metric in any sense or to satisf…
In this paper, we prove that Euclidean hypersurfaces with almost extremal extrinsic radius or λ1 have a spectrum that asymptotically contains the spectrum of the extremal sphere in the Reilly or Hasanis-Koutroufiotis Inequalities. We also consider almost extremal hypersurfaces which satisfy a supplementary bound on …
The paper finds self-similar solutions and critical radii for lens spaces in projective bundles.
problem Finding self-similar solutions and critical radii for lens spaces in projective bundles.
method Investigates lens spaces embedded in projective bundles with a specific gradient Ricci soliton structure.
result Explicit examples of Ricci-mean curvature flows are provided.
Critical nets in k-space have bounded edge lengths and vertices.
problem Understanding the structure and constraints of critical nets in k-dimensional space.
method Analyzing the properties of critical nets under fixed leaf positions and constraints.
result The total length of edges not incident with 1-valent vertices is bounded, and the degree and number of vertices are also bounded.
This guide simplifies high-probability regret bounds in empirical risk minimization.
problem High-probability regret bounds in empirical risk minimization.
method Modular presentation, three-step recipe, localized Rademacher complexity, local maximal inequalities, metric-entropy integrals.
result Recover familiar rates for various function classes and derive regret bounds for nuisance components.
We draw elliptic regularity results for 4-manifolds with an elliptic system, without Sobolev constant control. Direct use of analysis is circumvented; the results come mainly through geometric and topological arguments. In contrast to our previous paper, which worked predominantly on the scale of the curvature radius, …
We prove the existence of extremal domains for the first eigenvalue of the Laplace-Beltrami operator in some compact Riemannian manifolds of dimension n≥2, with volume close to the volume of the manifold. If the first (positive) eigenfunction φ0 of the Laplace-Beltrami operator over the manifold is a nonconst…
New method defends RL agents from poisoning attacks without MDP knowledge.
problem Poisoning attacks on RL systems can cause learning failures.
method Generic poisoning framework for online RL, Vulnerability-Aware Adversarial Critic Poison (VA2C-P).
result Successfully prevents RL agents from learning good policies or converging to target policies.
The thickness, NIR(K) of a knot or link K is defined to be the radius of the largest solid tube one can put around the curve without any self intersections, which is also known as the normal injectivity radius of K. For C^{1,1} curves K, NIR(K)=min{(1/2)DCSC(K),(1/(supkappa(K))))}, where kappa(K) is the generalized cur…
We build new examples of extremal domains with small prescribed volume for the first eigenvalue of the Laplace-Beltrami operator in some Riemannian manifold with boundary. These domains are close to half balls of small radius centered at a nondegenerate critical point of the mean curvature function of the boundary of t…
The paper explores the shape of filling-systole subspace in surface moduli space and critical points of systole function.
problem Understanding the structure and critical points of the filling-systole subspace in surface moduli space.
method Analyzing Teichmüller and Weil-Petersson distances to determine the proximity of points to the subspace.
result Most points in Mg are within a specific Teichmüller distance from Xg and have a certain distance from the thick part of Mg. The paper studies critical points of an energy functional on vector fields of Riemannian manifolds.
problem Analyzing critical points of an energy functional on vector fields of Riemannian manifolds.
method Introduced a G−symmetrization process and proved properties of critical points of the energy functional. result The infimum of the energy functional on spheres is achieved by G−invariant vector fields. The paper establishes estimates for convexity and injectivity radii in Riemannian manifolds.
problem Estimating convexity and injectivity radii in Riemannian manifolds.
method Pointwise and curvature-free estimates on convexity radius, injectivity radius, and local behavior of geodesics.
result Established estimates for convexity and injectivity radii in Riemannian manifolds.
Directly proves positive injectivity radius for Lie manifolds.
problem Injectivity radius positivity for Lie manifolds.
method Direct, geometric proof.
result Injectivity radius is positive for Lie manifolds.
Positive injectivity radius for manifolds with Lie structure at infinity.
problem Injectivity radius positivity for manifolds with specific boundary conditions.
method Lie groupoids to prove injectivity radius positivity.
result Injectivity radius is positive for manifolds with Lie structure at infinity.
Sharp inscribed radius estimate for curved surfaces.
problem Estimating the inscribed radius of curved surfaces.
method Proving a sharp estimate for inscribed radius under fully nonlinear curvature flows.
result The estimate is asymptotically sharp on cylinders.
Study on hypothesis testing for densities and multinomials, showing local minimax rates and critical radii.
problem Testing goodness-of-fit for distributions with varying number of categories or unbounded support.
method Developed novel tests for both discrete and continuous cases, considering local minimax rates and critical radii.
result Characterized the dependence of critical radii on the null hypothesis and provided adaptive tests.
The ratio of convexity radius over injectivity radius may be made arbitrarily small within the class of compact Riemannian manifolds of any fixed dimension at least two. This is proved using Gulliver's method of constructing manifolds with focal points but no conjugate points. The approach is suggested by a characteriz…
Uniform curvature bounds for regularized metrics with bounds on Ricci tensor and injectivity radius.
problem Bounding curvature of regularized metrics with constraints on Ricci tensor and injectivity radius.
method Mollification of riemannian metrics, uniform W2,p-harmonic radius bounds, Ricci tensor bounds, injectivity radius bounds. result Uniform estimate on the change of sectional curvature for regularized metrics.
Upper bound for conjugate radius in open manifolds with scalar curvature and spectrum constraints.
problem Bounding the conjugate radius of open manifolds with specific curvature and spectrum conditions.
method Established an upper bound using scalar curvature and bottom-of-spectrum constraints.
result For certain conditions, the conjugate radius is no more than π.
Proves upper bound on filling radius for manifolds with positive scalar curvature.
problem Bounding the filling radius of manifolds with positive scalar curvature.
method Quantitative operator K-theory and index theory.
result Proves a quantitative upper bound on the filling radius.
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.
Injectivity radius on Stiefel manifold is π.
problem Determining the injectivity radius of the compact Stiefel manifold.
method Utilized the property of geodesics being space curves of constant Frenet curvatures.
result The injectivity radius on the Stiefel manifold under the Euclidean metric is π.
Lower bound on boundary injectivity radius for specific tubes.
problem Estimating the boundary injectivity radius of Margulis tubes.
method Using curvature bounds to derive a lower bound.
result A lower bound on the boundary injectivity radius is provided.
Study gives bounds on filling radius for Riemannian manifolds.
problem Finding bounds on the filling radius of Riemannian manifolds.
method Curvature-dependent bounds for all closed manifolds and upper bounds for submersion and submetry cases.
result Upper and lower bounds on the filling radius for specific types of manifolds.
This paper analyzes how periodic and soft target updates stabilize linear Q-learning.
problem Theoretical explanation of stabilization mechanisms for linear Q-learning.
method Exact analysis using switched linear system dynamics and the joint spectral radius.
result Periodic and soft target updates can guarantee convergence to the exact projected Q-Bellman solution under specific conditions.
Defines John-Nirenberg radius for collapsing conformal metrics and proves a convergence theorem.
problem Analyzing collapsing conformal metrics in a fixed conformal class.
method Defining John-Nirenberg radius and proving convergence using curvature conditions.
result The John-Nirenberg radius is bounded below by a positive constant for collapsing conformal metrics.
The expected covering radius of a translation surface is bounded by a function of log g/g^(1/2).
problem Computing the expected covering radius of translation surfaces.
method Estimating the volume of the thin part of H_1(kappa) and using it to bound the covering radius.
result The expected covering radius is bounded above by a uniform multiple of ((log g)/g)^(1/2).
The paper proves estimates and theorems for Kähler manifolds.
problem Curvature conditions on Kähler manifolds.
method Volume comparison and rigidity theorems.
result Conjugate radius estimates for Kähler manifolds.
The ropelength of a space curve is usually defined as the quotient of its length by its thickness: the radius of the largest embedded tube around the knot. This idea was extended to space polygons by Eric Rawdon, who gave a definition of ropelength in terms of doubly-critical self-distances (local minima of the distanc…
Study finds the covering radius of RM(4,8) is 26.
problem Determining the covering radius of RM(4,8).
method Invented a lift by derivation invariant to classify B(5,6,8).
result Covering radius of RM(4,8) is 26.
Hardness result for approximating manifold radius.
problem Approximating the radius of triangulated manifolds.
method Proving NP-hardness for almost-polynomial approximation.
result It is NP-hard to approximate the hyperspherical radius up to an almost-polynomial factor.
We prove a formula for the normal injectivity radius(thickness)i(K,M)for C^{1,1} compact submanifolds K^k of complete Riemannian manifolds M^n in terms of geometric focal distance and double critical points. We also prove the C^1 compactness of the set of all compact submanifolds K contained in a compact subset D of a …
Clarifies definition of polarized canonical radius in Kahler Ricci flow.
problem Unclear definition of polarized canonical radius in Kahler Ricci flow.
method Clarification of the definition.
result Clarified definition of polarized canonical radius.
We give a characterization of critical points that allows us to define a metric invariant on all Riemannian manifolds M with a lower sectional curvature bound and an upper radius bound. We show there is a uniform upper volume bound for all such manifolds with an upper bound on this invariant. We generalize results by…
The study classifies critical points of systolic functions on hyperbolic surfaces.
problem Variational study of systolic functions on Teichmüller spaces.
method Geometric Voronoï theory and shearing coordinates.
result Complete classification of nondegenerate critical points.
We are concerned about the coarse and precise aspects of a priori estimates for Green's function of a regular domain for the Laplacian-Betrami operator on any 3≤n-dimensional complete non-compact boundary-free Riemannian manifold through the square Sobolev/Nash/logarithmic-Sobolev inequalities plus the rough and s…
The paper proves an area inequality for metric balls in Riemannian manifolds.
problem Proving an area inequality for metric balls in Riemannian manifolds.
method Analyzing metric balls B(p,R) in two-dimensional Riemannian manifolds. result Proves an area inequality Area(B(p,R))≥π8R2 for R less than half the convexity radius. The paper bounds bandwidth and focal radius for manifolds with positive isotropic curvature.
problem Bounding bandwidth and focal radius for manifolds with positive isotropic curvature.
method Using spectral properties of a twisted de Rham-Hodge operator.
result Upper bounds on bandwidth and focal radius are derived for hypersurfaces in PIC manifolds.