The paper studies singularities on parallels of tangent developable surfaces of frontal curves.
problem Understanding singularities on parallels of tangent developable surfaces.
method Generalization of tangent developable surfaces and parallel deformations for frontal curves in arbitrary dimensions.
result Classification of generic singularities on parallels of tangent developable surfaces for frontal curves in 3 or 4 dimensional Euclidean spaces.
Characterizes special curves on surface tangent bundles.
problem Understanding curves on surface tangent bundles.
method Characterization of Legendre and slant curves.
result Characterizations for N-Legendre and N-slant curves.
A directed curve is a possibly singular curve with well-defined tangent lines along the curve. Then the tangent surface to a directed curve is naturally defined as the ruled surface by tangent geodesics to the curve, whenever any affine connection is endowed with the ambient space. In this paper the local diffeomorphis…
Considering the tangent plane at a point to a surface in the four-dimensional Euclidean space, we find an invariant of a pair of two tangents in this plane. If this invariant is zero, the two tangents are said to be conjugate. When the two tangents coincide with a given tangent, then we obtain the normal curvature of t…
We give the complete solution to the local diffeomorphism classification problem of generic singularities which appear in tangent surfaces, in as wider situations as possible. We interpret tangent geodesics as tangent lines whenever a (semi-)Riemannian metric, or, more generally, an affine connection is given in an amb…
We give the complete solution to the local diffeomorphism classification problem of generic singularities which appear in tangent surfaces, in as wider situations as possible. We interpret tangent geodesics as tangent lines whenever a (semi-)Riemannian metric, or, more generally, an affine connection is given in an amb…
Study K-R flow on Hirzebruch surfaces, showing tangent flows are K-R flows with orbifold singularities.
problem Finite time singularities in Kähler-Ricci flow on Hirzebruch surfaces.
method Analyze tangent flows based at singular points.
result Tangent flows are K-R flows with orbifold singularities.
Researchers calculate Hofer-Zehnder capacity for twisted tangent bundles over surfaces.
problem Determining the Hofer-Zehnder capacity for specific geometric configurations.
method Analyzing constant magnetic fields on closed surfaces and using equivariant compactification.
result Explicit calculations and compactifications for phase and configuration spaces.
The paper classifies surfaces with pseudo-effective tangent bundles.
problem Understanding projective manifolds with pseudo-effective tangent bundles.
method Developed singular hermitian metrics on vector bundles and applied to projective manifolds.
result Projective manifolds with pseudo-effective tangent bundles admit a smooth fibration to a flat projective manifold.
In this paper, we define the inverse surface of a tangent developable surface with respect to the sphere S_{c}(r) with the center c∈E3 and the radius r in 3-dimensional Euclidean space E3. We obtain the curvatures, the Christoffel symbols and the shape operator of this inverse surface by …
It is given the diffeomorphism classification on generic singularities of tangent varieties to curves with arbitrary codimension in a projective space. The generic classifications are performed in terms of certain geometric structures and differential systems on flag manifolds, via several techniques in differentiable …
Extends first-order flexes of surfaces to second-order flexes.
problem Extending flexes of surfaces to higher order.
method Analyzes first-order flexes of smooth surfaces tangent to nonrigid surfaces.
result First-order flexes can be extended to second-order flexes.
Geodesics on modular surface yield arithmetic 3-manifolds.
problem Understanding arithmetic properties of modular surfaces.
method Constructing geodesics and analyzing their lifts.
result Complements of canonical lifts are arithmetic 3-manifolds.
Geodesics of the same type on curved surfaces are randomly distributed.
problem Distribution of geodesics of the same type on negatively curved surfaces.
method Asymptotic equidistribution with respect to a measure on the unit tangent bundle.
result Geodesics of the same type are asymptotically equidistributed with respect to a measure mS. Study shows unique tangent flow for Lagrangian surfaces with bounded mean curvature.
problem Understanding the behavior of Lagrangian surfaces with bounded mean curvature.
method Analyzing zero Maslov Lagrangian mean curvature flow in C2 with bounded mean curvature. result The tangent flow at a singular point is unique if the mean curvature stays uniformly bounded.
At any point of a surface in the four-dimensional Euclidean space we consider the geometric configuration consisting of two figures: the tangent indicatrix, which is a conic in the tangent plane, and the normal curvature ellipse. We show that the basic geometric classes of surfaces in the four-dimensional Euclidean spa…
In this study, we give the relationships between the conical curvatures of ruled surfaces drawn by the unit vectors of the ruling, central normal and central tangent of a regular ruled surface in the Euclidean -space. We obtain the differential equations characterizing slant ruled surfaces and if the reference ruled su…
The paper extends geometric surface properties to currents tangent to smooth distributions.
problem Understanding the geometric structure of currents tangent to smooth distributions.
method Analyzing integral and normal currents, focusing on their geometric properties and boundary.
result Integral currents behave like smooth surfaces, while normal currents have a more complex behavior.
Study shows how certain foliations in unit tangent bundles behave.
problem Characterizing behavior of foliations in unit tangent bundles.
method Analyzing intersections and properties of foliations.
result Certain partially hyperbolic diffeomorphisms are collapsed Anosov flows.
Solves recognition problem of frontal singularities.
problem Recognition of frontal singularities.
method Specified geometric frontal singularities, provided explicit normal forms, combined results from K. Saji and applied to tangent surfaces of null curves.
result Classification of singularities in tangent surfaces of null curves.
New surfaces show horocyclic flow isn't always minimal.
problem Complex dynamics on infinite fineness surfaces.
method Construction of infinite hyperbolic surfaces.
result Horocyclic flow is not minimal on infinite fineness surfaces.
The paper explores how the Gauss curvature of Riemannian surfaces can be represented as the divergence of a vector field.
problem Representing the Gauss curvature of Riemannian surfaces as the divergence of a vector field.
method Investigates the existence of a metric linear connection of zero curvature and its role in differential geometry.
result Provides conditions under which a Riemannian surface can be considered a generalized Berwald surface.
Unified study of surfaces using Clifford algebras.
problem Classifying immersed surfaces in various manifolds.
method Using Clifford algebras to construct formalism for immersed bilegendrian surfaces.
result Full classifications of immersed bilegendrian surfaces in the unit tangent bundle of the 3-sphere.
Veering branched surfaces help construct geodesic flows on curved surfaces.
problem Constructing geodesic flows on negatively curved surfaces.
method Introduce veering branched surfaces and surgeries, then use them to construct veering triangulations that correspond to geodesic flows.
result Explicit constructions of veering branched surfaces corresponding to geodesic flows on negatively curved surfaces.
A mathematical paradox shows secant planes don't always form a tangent plane, but some analogies hold with a specific vector product.
problem Secant planes of a two-variable smooth function do not always form a tangent plane, even for simple polynomials.
method Analogies with the one-variable case are explored, using Clifford's geometric vector product.
result Some analogies with the one-variable case still hold in the multi-variable context with a specific vector product.
The paper classifies degenerate almost complex surfaces in a nearly Kähler space.
problem Classifying degenerate almost complex surfaces in nearly Kähler spaces.
method Investigates two distinct cases based on the preservation of the tangent bundle under the almost product structure.
result Complete and explicit classification of degenerate almost complex surfaces in nearly Kähler spaces.
Study defines hyper-dual spheres and ruled surfaces, proving geometric relationships.
problem Understanding geometric properties of hyper-dual spheres and ruled surfaces.
method Defined hyper-dual spheres, developed ruled surfaces, and established geometric relationships.
result Proved isomorphism between hyper-dual sphere and tangent bundle, and geometric interpretation of ruled surfaces.
This paper is a continuation of the previous paper of the author[M]. We show that an affine deformation space of a hyperbolic surface of type (g,b) can be parametrized by Margulis invariants and affine twist parameters with a certain decomposition of the surface, which are associated with the Fenchel-Nielsen coordinate…
Study flat surfaces along curves in higher-dimensional spaces.
problem Existence and uniqueness of flat surfaces along curves.
method Explicit parametric construction using flat surfaces as ruled surfaces with stable tangent planes.
result Explicit construction of flat approximations of hypersurfaces along curves.
In the tangent plane at any point of a surface in the four-dimensional Euclidean space we consider an invariant linear map of Weingarten-type and find a geometrically determined moving frame field. Writing derivative formulas of Frenet-type for this frame field, we obtain eight invariant functions. We prove a fundament…
We classify compact Kähler manifolds with semi-positive holomorphic bisectional and big tangent bundles. We also classify compact complex surfaces with semi-positive tangent bundles and compact complex 3-folds of the form P(T∗X) whose tangent bundles are nef. Moreover, we show that if X is a Fano manifold such t…
Study shows generic surfaces avoid complex flow patterns.
problem Understanding flow patterns of surfaces in 3D space.
method Analyzes mean curvature flow of closed surfaces in R3. result Non-cylindrical self-shrinkers cannot arise generically.
Regularizes 3D inverse scattering with tangent-point energy for better solutions.
problem Ill-conditioned inverse obstacle scattering problems in 3D.
method Tikhonov regularization using tangent-point energy to penalize surface roughness and ensure well-posedness.
result Regularized solutions converge to true solution as noise level decreases.
New proof using Bochner technique for compact surfaces.
problem Proving a classical result about compact surfaces.
method Application of Bochner formula and Whitney embedding theorem.
result Compact orientable surfaces with no tangent vector field zeroes are diffeomorphic to a torus.
Study bi-Hermitian metrics on complex surfaces and solve geometric PDEs.
problem Construct canonical metrics on complex surfaces with split tangent bundle.
method Introduced new fully non-linear geometric PDEs and established smooth solutions.
result Solved the prescribed Bismut Ricci problem on complex surfaces.
In [31,32,33] the Gauss-Bonnet formulas for coherent tangent bundles over compact oriented surfaces (without boundary) were proved. We establish the Gauss-Bonnet theorem for coherent tangent bundles over compact oriented surfaces with boundary. We apply this theorem to investigate global properties of maps between surf…
Uniqueness of conical flows helps understand singularities in surface flows.
problem Understanding singularities in surface flows.
method Analyzing asymptotically conical tangent flows.
result Uniqueness of multiplicity-one asymptotically conical tangent flows.
The paper derives Gauss-Bonnet formulas for mappings between surfaces with boundary.
problem Calculating topological invariants for mappings between surfaces with boundaries.
method Defining singular points, constructing coherent tangent bundles, and applying Gauss-Bonnet formulas.
result Derives two Gauss-Bonnet type formulas for mappings between surfaces with boundaries.
We study the totally null surfaces of the neutral Kaehler metric on certain 4-manifolds. The tangent spaces of totally null surfaces are either self-dual (α-planes) or anti-self-dual (β-planes) and so we consider α-surfaces and β-surfaces. The metric of the examples we study, which include the spaces of oriente…
Partial coverings of hyperbolic surfaces equidistribute with geodesics.
problem Equidistribution of partial coverings defined from geodesics.
method Sequence of geodesics equidistributing in unit tangent bundle implies equidistribution of associated partial coverings.
result Partial coverings equidistribute with a sequence of geodesics.
The study of equidistants for families of surfaces, focusing on specific ratios of tangent planes.
problem Understanding the geometric properties of surfaces and their tangent planes.
method Local study of affine equidistants, critical value analysis of 2-parameter unfoldings, geometric classification of singularities.
result Classification of singularities in equidistants near the supercaustic chord.
The paper studies how surfaces move by mean curvature flow and what happens at singular points.
problem Understanding the behavior of surfaces moving by mean curvature flow at singular points.
method Proves that tangent flows at singular times are smooth shrinkers, with a new local Gauss-Bonnet formula.
result Smooth shrinkers without branch points if the initial surface is embedded in 3-manifold.
Study on curves around a Whitney umbrella focusing on geodesic and normal curvatures.
problem Analyzing geometric properties of curves around a specific surface.
method Examined geodesic and normal curvatures, ruled surfaces, and normal developable surfaces.
result Obtained functions representing geometry on a Whitney umbrella.
The paper derives new Gauss-Bonnet formulas for frontal bundles over surfaces with boundary.
problem Deriving new formulas for coherent tangent bundles over surfaces with boundary.
method Defining frontal bundles and applying Gauss-Bonnet theorems to derive formulas.
result Four new Gauss-Bonnet type formulas for frontal bundles are derived.
The paper classifies helix curves on a pseudo-Riemannian surface.
problem Classifying helix curves on pseudo-Riemannian surfaces.
method Analyzing geodesic flow vector fields and pseudo-Riemannian metrics.
result All helix curves are circular helixes with constant curvature and torsion.
Study on homeomorphisms preserving C1 curves on surfaces.
problem Characterizing homeomorphisms that preserve C1 curves. method Local conditions on induced map on projective tangent bundle.
result Characterization of Homeo1(S) for most closed surfaces. In this note, we combine the work of Ilmanen and of Colding-Ilmanen-Minicozzi to observe a uniqueness property for tangent flows at the first singular time of a smooth mean curvature flow of a closed surface in 3-dimensional Euclidean space. Specifically, if, at a fixed singular point, one tangent flow is a positive in…
Unique entropy measure found for geodesic flows on certain surfaces.
problem Finding a unique measure of maximal entropy for geodesic flows.
method Analyzing geodesic flows on surfaces without conjugate points.
result Proved existence of a unique measure of maximal entropy for geodesic flows on certain surfaces.