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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,932 papers · 148 categories

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108217325433 · May 202619922001200920172026
48 results for min bounding sphere

The paper bounds the min-max width of embedded circles on spheres and manifolds.

problem Bounding the min-max width of embedded circles on spheres and manifolds.
method Inducing a sweepout by pairs of points in embedded circles from a given sweepout of the sphere by closed curves.
result Lower bounds for the Birkhoff min-max invariant of a Riemannian sphere in terms of the min-max width of its embedded circles.

We accelerate min-max optimization and apply it to minimal bounding sphere problems.

problem Min-max optimization and minimal bounding sphere problems.
method Smoothing the max operator and applying it to the minimal bounding sphere problem.
result Achieve (1+ε)(1+\varepsilon)-approximation of minimal bounding sphere in ildeO(nd/ε) ilde{O}(n d /\sqrt{\varepsilon}) time.

Proves existence of special 2-spheres in curved 3-spaces.

problem Existence of constant mean curvature 2-spheres in Riemannian 3-spheres.
method Develops a min-max scheme for a weighted Dirichlet energy functional, using bi-harmonic approximation, derivative estimates, and Morse index estimates.
result Proves existence for almost every mean curvature and all for positively curved 3-spheres.

We show that the sum of the Morse indices of the Willmore spheres realising the width of Willmore type sweep-outs is bounded by the number of the parameters of the min-max. As an application, we deduce that among the true Willmore spheres realising the min-max sphere eversion, at most one of them one has index 1, while…

2018-08-23abs ↗pdf ↗

The paper characterizes eigenvalues of surfaces using min-max quantities for harmonic maps.

problem Characterizing eigenvalues of surfaces using harmonic maps.
method Defining min-max quantities associated with sphere-valued maps and proving eigenvalue bounds.
result Identifies Λ1(M,c)Λ_1(M,c) and Λ2(M,c)Λ_2(M,c) with min-max quantities for sphere-valued maps.

The paper solves min-max widths on a 3-sphere and strengthens multiplicity theorems.

problem Which min-max widths of the unit 3-sphere lie between 2π22π^2 and 8π?
method Homological min-max theory and stronger versions of multiplicity one theorems.
result Proves the 10th to 13th min-max widths of the unit 3-sphere lie between 2π22π^2 and 8π.

New geometric invariant from min-max width of spheres on Riemannian 2-spheres.

problem Understanding the min-max width of spheres associated to distance functions.
method Application of min-max methods to pairs of points on Riemannian 2-spheres.
result The min-max width does not always equal half the length of a simple closed geodesic.

New examples of non-bumpy metrics on spheres and projective spaces with multiplicity.

problem Finding non-bumpy metrics with multiplicity on spheres and projective spaces.
method New area-and-separation estimate for minimal hypersurfaces with Morse index two.
result First examples of non-bumpy metrics with multiplicity on (n+1)(n+1)-spheres and projective spaces.

Improved eigenvalue bounds for minimal hypersurfaces in spheres.

problem Proving bounds on the first eigenvalue of minimal hypersurfaces in spheres.
method Using the Laplacian operator and properties of the second fundamental form, derived a new lower bound for the first eigenvalue.
result Improved lower bound for the first eigenvalue of minimal hypersurfaces in spheres.

The paper proves the existence of H-spheres with arbitrary codimensions in certain Riemannian manifolds.

problem Existence of H-spheres with arbitrary codimensions in closed Riemannian manifolds.
method Min-max theory and Morse index analysis.
result Existence of branched immersed H-spheres with controlled Morse index and arbitrary codimensions.

Entropy is a natural geometric quantity measuring the complexity of a surface embedded in R3\mathbb{R}^3. For dynamical reasons relating to mean curvature flow, Colding-Ilmanen-Minicozzi-White conjectured that the entropy of any closed surface is at least that of the self-shrinking two-sphere. We prove this conjecture …

2015-09-21abs ↗pdf ↗

The 3-sphere has either 2 minimal 2-spheres or an optimal foliation by 2-spheres.

problem Proving existence of minimal 2-spheres or optimal foliations in arbitrary Riemannian 3-spheres.
method Analyzing the properties of arbitrary Riemannian metrics on 3-spheres.
result The existence of at least two minimal 2-spheres or an optimal foliation in 3-spheres with arbitrary metrics.

In this paper we consider min-max minimal surfaces in three-manifolds and prove some rigidity results. For instance, we prove that any metric on a 3-sphere which has scalar curvature greater than or equal to 6 and is not round must have an embedded minimal sphere of area strictly smaller than 4π and index at most one…

2011-05-23abs ↗pdf ↗

How large can be the width of Riemannian three-spheres of the same volume in the same conformal class? If a maximum value is attained, how does a maximising metric look like? What happens as the conformal class changes? In this paper, we investigate these and other related questions, focusing on the context of Simon-Sm…

2018-09-10abs ↗pdf ↗

The paper constructs new non-trivial harmonic maps into higher-dimensional target manifolds.

problem Existence of non-trivial harmonic maps into higher-dimensional target manifolds.
method Perturbative argument, refined neck-analysis, energy identity, min-max problems.
result Construction of an infinite family of new null-homotopic nn-harmonic nn-spheres.

The paper proves the existence of at least 4 embedded minimal tori in a three-sphere with positive Ricci curvature.

problem Proving the existence of embedded minimal tori in three-spheres with positive Ricci curvature.
method The proof relies on a multiplicity one theorem for the Simon-Smith min-max theory.
result There exist at least 4 distinct embedded minimal tori in the three-sphere with positive Ricci curvature.

We characterize the Zoll Riemannian metrics on a given simply connected spin closed manifold as those Riemannian metrics for which two suitable min-max values in a finite dimensional loop space coincide. We also show that on odd dimensional Riemannian spheres, when certain pairs of min-max values in the loop space coin…

2018-09-23abs ↗pdf ↗

Proves a generalized isoperimetric inequality for spheres in dimensions 4 and above.

problem Proving a generalized isoperimetric inequality for spheres in dimensions 4 and above.
method Reduced to a theorem about thick embeddings of graphs, proved using Kolmogorov-Barzdin theorem and max-flow min-cut theorem. Counterexample in dimension 3 uses coarea inequality and winding number computation.
result A generalized isoperimetric inequality for spheres in dimensions 4 and above.

New minimal surface doublings of Clifford Torus improve bounds on minimal surfaces in S^3.

problem Proving bounds on minimal surfaces in S^3 with fixed genus.
method Applying a general theorem to produce new minimal doublings of the Clifford Torus, using min-max methods, and verifying Yau's conjecture.
result Improved quadratic lower bound for the number of embedded minimal surfaces in S^3 with prescribed genus.

In this paper, we build up a min-max theory for minimal surfaces using sweepouts of surfaces of genus g2g\geq 2. We develop a direct variational methods similar to the proof of the famous Plateau problem by J. Douglas and T. Rado. As a result, we show that the min-max value for the area functional can be achieved by a …

2011-11-27abs ↗pdf ↗

We obtain in arbitrary codimension a removability result on the order of singularity of Willmore surfaces realising the width of Willmore min-max problems on spheres. As a consequence, out of the twelve families of non-planar minimal surfaces in R3\mathbb{R}^3 of total curvature greater than 12π-12π, only three of them …

2019-04-22abs ↗pdf ↗

For a Riemannian metric gg on the two-sphere, let min(g)\ell_{\min}(g) be the length of the shortest closed geodesic and max(g)\ell_{\max}(g) be the length of the longest simple closed geodesic. We prove that if the curvature of gg is positive and sufficiently pinched, then the sharp systolic inequalities \[ \ell_{\rm min}(g…

2014-10-28abs ↗pdf ↗

This paper bounds min-entropy leakage for Blowfish privacy using graph symmetries.

problem Bounding min-entropy leakage for Blowfish privacy mechanisms.
method Organizing analysis over symmetrical partitions corresponding to orbits of graph automorphism groups.
result Demonstrates a construction meeting the bound with asymptotic equality, showing tightness.

Lower bounds found for nonconvex-strongly-concave min-max optimization problems.

problem Finding stationary points in nonconvex-strongly-concave min-max optimization.
method Provided lower bounds for first-order oracle complexity.
result Lower bounds of Ω(√κε⁻²) for deterministic oracles and Ω(√κε⁻² + κ¹/₃ε⁻⁴) for stochastic oracles.

The study counts minimal surfaces in 3-manifolds with positive Ricci curvature.

problem Counting minimal surfaces in 3-manifolds with positive Ricci curvature.
method An enumerative min-max theorem linking surface counts to topological properties.
result Every 3-sphere of positive Ricci curvature contains at least 4 embedded minimal surfaces of genus 2.

Assume that M is a compact n-dimensional manifold and that N is obtained by surgery along a k-dimensional sphere, k\le n-3. The smooth Yamabe invariants σ(M) and σ(N) satisfy σ(N)\ge min (σ(M),Λ) for Λ>0. We derive explicit lower bounds for Λin dimensions where previous methods failed, namely for (n,k)\in {(4,1),(5,1),…

2012-04-05abs ↗pdf ↗

The study finds a way to create minimal surfaces with specific shapes in 3-manifolds.

problem Creating minimal surfaces with prescribed genus in 3-manifolds with positive Ricci curvature.
method Develops a min-max theory and shows deformability of surfaces in a generic metric.
result Establishes a theorem for producing minimal surfaces with prescribed genus.

We compute the kk-width of a round 22-sphere for k=1,,8k=1,\ldots,8 and we use this result to show that unstable embedded closed geodesics can arise with multiplicity as a min-max critical varifold.

2016-01-06abs ↗pdf ↗