Zero entropy found in entire Grauert tubes of certain manifolds.
problem Analyzing the geodesic flow on Grauert tubes with zero entropy.
method Examined entire Grauert tubes on real analytic Riemannian manifolds.
result Geodesic flow on entire Grauert tubes has zero topological entropy.
Study proves certain Zoll manifolds with entire Grauert tubes are isometric.
problem Characterizing Zoll manifolds with entire Grauert tubes.
method Computed algebraic indices of tangent bundles; proved isometry.
result Any Zoll manifold of type HP^2 with entire Grauert tube is isometric to canonical HP^2.
Partial answer to affineness of entire Grauert tubes, with Stein manifold criterion.
problem Affineness of entire Grauert tubes
method Generalized Demailly's criterion for Stein manifolds
result Complement of a codimension-one subset is affine
Zoll manifolds with entire Grauert tubes are proven to be standard complex projective spaces.
problem Characterizing Zoll manifolds with entire Grauert tubes.
method Isometric comparison to CPn with the canonical metric. result Zoll manifolds of type CPn with entire Grauert tubes are isometric to CPn. Study on SU(2) Lie group tubes with left-invariant metrics.
problem Determine when SU(2) Grauert tubes are entire.
method Analyze left-invariant metrics on SU(2) with complete geodesic flow.
result Find a new obstruction to SU(2) tubes being entire.
To every real analytic Riemannian manifold M there is associated a complex structure on a neighborhood of the zero section in the real tangent bundle of M. This structure can be uniquely specified in several ways, and is referred to as a Grauert tube. We say that a Grauert tube is entire if the complex structure can be…
Researchers prove a complex geometric conjecture about certain manifolds.
problem Compact simply connected Riemannian manifolds with nonnegative sectional curvature.
method Assumption of entire Grauert tube and real analytic structure.
result Compact simply connected Riemannian manifolds with entire Grauert tube are rationally elliptic.
Weyl's tube formula holds for various cross-sections under symmetry conditions.
problem Can the volume of tubes around submanifolds be calculated for non-round cross-sections?
method Investigated the volume of tubes with general cross-sections D under symmetry conditions.
result The volume of tubes around submanifolds can be calculated for general cross-sections under symmetry conditions.
Reconstruction of density functions and their characteristic functions by radial basis functions with scattered data points is a popular topic in the theory of pricing of basket options. Such functions are usually entire or admit an analytic extension into an appropriate tube and "bell-shaped" with rapidly decaying tai…
Computes tube formulas for valuations in complex space forms.
problem Computing values of valuations on complex space forms.
method Develops tube formulas for valuations in complex space forms and generalizes classical formulas.
result Generalizes classical formulas of Weyl, Gray and others.
The paper defines marginal tubes and proves their null nature.
problem Understanding the geometry of spacelike surfaces in spacetimes.
method Introducing marginal tubes and studying spacelike surfaces with double null coordinates.
result If every spacelike section of a marginal tube is a marginal surface, then the marginal tube is null.
Study on metric properties near boundary of tube domains.
problem Behavior of complete Kahler-Einstein metric near boundary.
method Estimates of metric and holomorphic bisectional curvatures.
result Obtained estimates near weakly pseudoconvex boundary points.
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 on non-Gromov hyperbolic tube domains and their geometric properties.
problem Characterizing non-Gromov hyperbolic tube domains with convex bases.
method Provided a criterion for non-Gromov hyperbolicity, studied Hilbert metric, and continuity properties of complex geodesics.
result Similarity of geometry of tube domains and convex domains, connections between metrics.
H. Hotelling proved that in the n-dimensional Euclidean or spherical space, the volume of a tube of small radius about a curve depends only on the length of the curve and the radius. A. Gray and L. Vanhecke extended Hotelling's theorem to rank one symmetric spaces computing the volumes of the tubes explicitly in these …
New method for flexible tubes and structures, enabling rigid-foldability.
problem Creating flexible tubes with rigid-foldability.
method Discrete, semi-discrete, and smooth construction of surfaces (T-hedra and profile-affine surfaces).
result Unified treatment of continuous flexible structures composed of tubes.
Characterizes Calabi-Yau Hodge structures over tube domains.
problem Characterizing Hodge structures over specific domains.
method Using characteristic forms to characterize variations of Hodge structures.
result Characteristic forms uniquely identify Calabi-Yau Hodge structures over tube domains.
Classifies tube domains with specific properties in complex spaces.
problem Classifying tube domains with unique geometric properties.
method Analyzes tube domains in complex spaces with homogeneous boundaries and specific Levi forms.
result Classifies tube domains with large automorphism groups in arbitrary dimensions.
Study on volume of tubes and concentration in Riemannian geometry.
problem Understanding concentration loci in Riemannian manifolds and their relation to tube volumes.
method Provided a general formula for tube volumes, specialized to totally geodesic submanifolds, and investigated concentration loci.
result Explicitly proved concentration for codimension one cases and explored characterizations in Wasserstein and Box distances.
Sharp bounds found for distances between specific geometric shapes in hyperbolic space.
problem Finding effective distances between specific geometric shapes (tori) in hyperbolic 3-manifolds.
method Sharp, effective bounds on distances between tori of fixed injectivity radius.
result Effective bounds on distances between specific geometric shapes in hyperbolic space.
A surface is called a tube if its level-sets with respect to some coordinate function (the axis of the surface) are compact. Any tube of zero mean curvature has an invariant, the so-called flow vector. We study how the geometry of the Gaussian image of a higher-dimensional minimal tube M is controlled by the angle alph…
Formula for tube volume on special geometric manifolds.
problem Calculating volumes of geometric structures.
method Using Einstein constant and polarization volume.
result Formula for renormalized tube volume.
In this paper, we investigate the volume-prserving mean curvature flow starting from a tube (of nonconstant radius) over a compact closed domain of a reflective submanifold in a symmetric space. We prove that the tubeness is preserved along the flow under certain conditions.
We consider an example of tubes of hypersurfaces in Euclidean space and generalise the tube formula to supercase. By this we assign to a point of the hypersurface in superspace a rational characteristic function. Does this rational function appear when we calculate the zeta-function of an arithmetic variety?
We classify the torsion pairs in a tube category and show that they are in bijection with maximal rigid objects in the extension of the tube category containing the Pruefer and adic modules. We show that the annulus geometric model for the tube category can be extended to the larger category and interpret torsion pairs…
We obtain upper bounds for the first Dirichlet eigenvalue of a tube around a complex submanifold P of CPn which depends only on the radius of the tube, the degrees of the polynomials defining P and the first eigenvalue of some model centers of the tube. The bounds are sharp on these models. Moreover, when the mo…
Extends tube volume estimates using integral curvature bounds.
problem Estimating volumes of tubes around submanifolds.
method Generalizes Heintze-Karcher inequality to k-Ricci curvature bounds. result Volume estimates for tubes around submanifolds using integral curvature bounds.
Estimates Betti numbers of loop spaces of compact manifolds.
problem Estimating Betti numbers of loop spaces of compact manifolds.
method Using finite Grauert tubes to provide an effective estimate.
result Implication of polynomial estimate in the limit of tube radius.
Researchers solved a geometry paradox for creased tubes.
problem Resolving the paradox of Gaussian curvature in creased tubes.
method Calculated Gaussian curvature in terms of rate of change of solid angle, dependent on fold angle and curvature.
result Gaussian curvature is zero overall despite the surface being doubly-curved.
Characterizes harmonic manifolds using tube properties.
problem Understanding harmonic manifolds through tube properties.
method Analyzes properties of tubes in harmonic manifolds and geodesic segments.
result Characterizes harmonic manifolds using tube properties for geodesic segments and arc lengths.
In this paper, we study the spectrum of quantum tubes. Under certain intrinsic assumptions of the asymptotically flat submanifold of the Euclidean space, we prove the existence of the ground state of the quantum tube. The work is a generalization of Duclos, Exner and Krejcirik (CMP, 223(1), 13-28, 2001) and ourselves(m…
We give a geometric model for a tube category in terms of homotopy classes of oriented arcs in an annulus with marked points on its boundary. In particular, we interpret the dimensions of extension groups of degree 1 between indecomposable objects in terms of negative geometric intersection numbers between correspondin…
New formula for curvatures of curves in n-dimensional space.
problem Calculating curvatures of curves in high-dimensional spaces.
method Explicit formula for curvatures using derivatives.
result Generalization of Pappus' theorems to higher dimensions.
Explicit Taylor series for the volume of tubes in Lie groups
problem Computing the volume of tubes in riemannian manifolds
method Using bi-invariant metrics
result Explicit Taylor series for the volume of a tube in a Lie group
Study on tubes with specific Gauss map properties in 3D space.
problem Characterizing surfaces with a specific Gauss map property in 3D space.
method Analyzing tubes in Euclidean 3-space with Gauss map n satisfying ΔIn = Λn.
result Circular cylinders are the only surfaces of coordinate finite I-type Gauss map.
First we investigate the evolutions of the radius function and its gradient along the volume-preserving mean curvature flow starting from a tube (of nonconstant radius) over a compact closed domain of a reflective submanifold in a symmetric space under certain condition for the radius function. Next, we prove that the …
Study constant mean curvature tubes in homogeneous spaces.
problem Global geometry of constant mean curvature tubes.
method Screw-motion invariants, foliation, numerical isoperimetric profile.
result Foliation result and embeddedness proof.
We establish the adiabatic dissapearance of Seiberg-Witten tunnelings on tubes R x N, where N is an S^1 fibration over a Riemann surface.
The study shows that the visible range from a point on harmonic manifolds follows an exponential distribution.
problem Understanding the visible range from a point on harmonic manifolds.
method Analyzing Poisson Boolean models on harmonic manifolds, focusing on the geometric mechanism of tube volumes around geodesic segments.
result The visible range from a point on harmonic manifolds follows an exponential distribution.
The Dirichlet Laplacian in curved tubes of arbitrary cross-section rotating with respect to the Tang frame along infinite curves in Euclidean spaces of arbitrary dimension is investigated. If the reference curve is not straight and its curvatures vanish at infinity, we prove that the essential spectrum as a set coincid…
We obtain various estimates of the life-time of two-dimensional minimal tubes in R^3 by potential theory methods.
The paper characterizes D'Atri spaces using total scalar curvature of hemispheres.
problem Characterizing D'Atri spaces using geometric properties.
method Characterization of D'Atri spaces via total scalar curvature of geodesic hemispheres.
result A 3D Riemannian manifold is a D'Atri space if and only if the total scalar curvature of tubes about geodesic segments holds.
The study examines constant mean curvature tubes around geodesics in specific 3-manifolds.
problem Investigating constant mean curvature surfaces in homogeneous 3-manifolds.
method Analyzing horizontal tubes foliating spaces under certain conditions.
result Horizontal tubes foliate spaces under specific curvature conditions.
New theory classifies knotted spheres in 4D space.
problem Classifying knotted punctured spheres in 4D space.
method Diagrammatic theory of welded graphs, Tube map extension, Milnor invariants.
result Complete link-homotopy classification of knotted punctured spheres.
Tubes in manifolds require wide spaces.
problem Embedding constraints in Riemannian manifolds.
method Analyzing uniformly thick tubular neighborhoods.
result Conditions for manifold embeddings with wide tubes.
As this is for the Bulletin of the A.M.S., it is not only a review of Alexander Isaev's Spherical Tube Hypersurfaces but also a brief introduction to CR geometry.
This note investigates the so-called Tube map which connects welded knots, that is a quotient of the virtual knot theory, to ribbon torus-knots, that is a restricted notion of fillable knotted tori in the 4-sphere. It emphasizes the fact that ribbon torus-knots with a given filling are in one-to-one correspondence with…
Proves Steiner and tube formulae for 3D contact sub-Riemannian surfaces.
problem Calculating surface properties in complex geometric structures.
method Develops a local Steiner formula for regular surfaces in 3D contact sub-Riemannian manifolds.
result Establishes a formula for surface expansion in arbitrary regions of contact sub-Riemannian manifolds.