The paper constructs all cmc hypersurfaces with two principal curvatures.
problem Finding all hypersurfaces with constant mean curvature and two principal curvatures.
method Explicit immersions and parameter analysis for hypersurfaces in space forms.
result The family of cmc hypersurfaces with two principal curvatures depends on two parameters, H and C.
In this paper are determined the principal curvatures and principal curvature lines on canal surfaces which are the envelopes of families of spheres with variable radius and centers moving along a closed regular curve in R^3. By means of a connection of the differential equations for these curvature lines and real Ricc…
The paper classifies and determines properties of specific hypersurfaces in complex hyperbolic quadrics.
problem Analyzing Hopf hypersurfaces with constant principal curvatures in complex hyperbolic quadrics.
method Classification and determination of principal curvatures for hypersurfaces with different numbers of distinct curvatures.
result Classification and determination of principal curvatures for Hopf hypersurfaces with up to four distinct values.
We find the first examples of real hypersurfaces with two nonconstant principal curvatures in complex projective and hyperbolic planes, and we classify them. It turns out that each such hypersurface is foliated by equidistant Lagrangian flat surfaces with parallel mean curvature or, equivalently, by principal orbits of…
The paper studies Einstein hypersurfaces in a specific warped product space.
problem Investigating Einstein hypersurfaces in a warped product space.
method Analyzing the principal curvatures and using multiply warped product structure.
result Hypersurfaces have at most three distinct principal curvatures and are locally multiply warped products.
Study on hypersurfaces with specific curvature conditions.
problem Characterizing hypersurfaces with certain curvature properties.
method Defined and analyzed the Opozda-Verstraelen affine curvature tensor for hypersurfaces.
result Conditions for pseudosymmetry types of hypersurfaces with specific curvature properties.
Let x be an m-dimensional umbilic-free hypersurface in an (m+1)-dimensional unit sphere Sm+1(m≥3). One of important questions is to classify hypersurfaces with two distinct principal curvatures. In this paper, we classify and explicitly express the hypersurfaces with two distinct principal curvat…
We classify all real hypersurfaces with three distinct constant principal curvatures in complex hyperbolic spaces of dimension greater than two.
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.
The paper studies mean curvature flows on specific orbits of Hermann actions.
problem Analyzing mean curvature flows on principal orbits of Hermann actions.
method Using Mathematica to illustrate and calculate the flows and orbits.
result The minimal principal orbit's position is calculated and illustrated.
We classify the homogeneous and isoparametric hypersurfaces of S2×S2. In the classification, besides the hypersurfaces S1(r)×S2,r∈(0,1], it appears a family of hypersurfaces with three different constant principal curvatures and zero Gauss-Kronecker curvature. …
The paper classifies various types of hypersurfaces in a product space.
problem Classifying hypersurfaces in a specific product space.
method Analyzing hypersurfaces with constant curvatures, product angle functions, and additional conditions.
result Different types of hypersurfaces are classified based on their properties.
We classify real hypersurfaces in complex space forms with constant principal curvatures and whose Hopf vector field has two nontrivial projections onto the principal curvature spaces. In complex projective spaces such real hypersurfaces do not exist. In complex hyperbolic spaces these are holomorphically congruent to …
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…
The paper proves properties of triharmonic CMC hypersurfaces with specific curvature conditions.
problem Characterizing triharmonic CMC hypersurfaces with distinct principal curvatures.
method Analyzing critical points of the tri-energy and applying geometric properties.
result Proves conditions for constant scalar curvature and minimality of hypersurfaces.
It is known that hypersurfaces in CPn or CHn for which the number g of distinct principal curvatures satisfied g≤2 must belong to a standard list of Hopf hypersurfaces with constant principal curvatures, provided that n≥3. In this paper, we construct a 2-parameter family of non-Hopf hypersurfaces in…
New discretizations of principal curvature lines discovered.
problem Discretizing principal curvature line parametrizations.
method Generalization of polar pairs of line congruences in the Lie quadric.
result New discretizations of orthogonal and Gauss-orthogonal parametrizations.
Paper corrects a proof about biharmonic hypersurfaces with three distinct curvatures.
problem Proving constant mean curvature for biharmonic hypersurfaces with three distinct principal curvatures.
method Analyzing the resultant of polynomials to identify a special case.
result In the special case, the hypersurface still has constant mean curvature.
The study classifies hypersurfaces in quaternionic space forms with constant principal curvatures.
problem Classifying hypersurfaces in quaternionic space forms with specific curvature properties.
method Analyzing curvature-adapted real hypersurfaces in non-flat quaternionic space forms HPm and HHm. result Classification of hypersurfaces including geodesic hyperspheres, tubes, and specific examples in HPm and HHm. We prove that an isoparametric hypersurface with four principal curvatures and multiplicity pair (7,8) is either the one constructed by Ozeki and Takeuchi, or one of the two constructed by Ferus, Karcher, and Münzner. This completes the classification of isoparametric hypersurfaces in spheres that É. Cartan initiated…
This paper establishes the geometric structure of the lines of principal curvature of a hypersurface immersed in R4 in a neighborhood of the set S of its principal curvature singularities, consisting of the points at which atF least two principal curvatures are equal. Under generic conditions d…
We study submanifolds whose principal curvatures, counted with multiplicities, do not depend on the normal direction. Such submanifolds, which we briefly call CPC submanifolds, are always austere, hence minimal, and have constant principal curvatures. Well-known classes of examples include totally geodesic submanifolds…
Study on isoparametric and constant-curvature hypersurfaces in Finsler spaces.
problem Characterizing and constructing hypersurfaces with specific curvature properties in Finsler geometry.
method Analyzing isoparametric and constant-curvature hypersurfaces on Randers manifolds.
result Construction of a conformally flat Randers manifold with nonisoparametric hyperplanes of constant curvatures.
Study on discrete surfaces with constant principal curvature for nanocarbon applications.
problem Understanding discrete geometry properties of nanocarbon materials.
method Developed discrete surface theory on 3-ary oriented trees, defined discrete principal directions, constructed examples of discrete CPC surfaces.
result Construction of discrete constant principal curvature surfaces, including discrete CPC tori.
Compact Dupin hypersurfaces without constant Lie curvatures found.
problem Finding compact Dupin hypersurfaces with non-constant Lie curvatures.
method Two constructions of compact proper Dupin hypersurfaces in Sn. result Examples of compact proper Dupin hypersurfaces without constant Lie curvatures.
Paper finds conditions for minimal hypersurfaces in S^6 with constant scalar curvature.
problem Finding conditions for minimal hypersurfaces in S^6 with constant scalar curvature.
method Assumptions on principal curvatures for isoparametric hypersurfaces.
result Rigidity result: Hypersurfaces with exactly two distinct principal curvatures are Clifford tori.
Study behavior of curvatures near singular points of frontals.
problem Understanding frontals near singular points.
method Investigate principal curvatures and vectors near singular points of frontals.
result Extend Ribaucour transformations to frontals with singular points.
Study the geometry of bifurcation sets for specific types of functions.
problem Understanding the structure of bifurcation sets for specific types of functions.
method Using blow-ups and parametrization, investigate the Gaussian curvature, principal curvatures, and curve behavior.
result Bifurcation sets of D4±-functions can be parametrized as surfaces in R3. Classifies surfaces with special curvature properties.
problem Rotational surfaces with specific curvature conditions.
method Classifies surfaces with rotationally symmetric norms and linear curvature relations.
result Rotational surfaces with linearly related curvatures are classified.
The notion of ideal immersions was introduced by the author in 1990s. Roughly speaking, an ideal immersion of a Riemannian manifold into a real space form is a nice isometric immersion which produces the least possible amount of tension from the ambient space at each point. In this paper, we classify all ideal hypersur…
The paper classifies PMCV hypersurfaces in non-flat pseudo-Riemannian space forms.
problem Characterizing PMCV hypersurfaces in non-flat pseudo-Riemannian space forms.
method Analyzing the properties of hypersurfaces with at most two distinct principal curvatures.
result PMCV hypersurfaces are either minimal or locally isoparametric.
The paper classifies Hopf hypersurfaces with constant curvatures on complex quadrics.
problem Classifying Hopf hypersurfaces with specific curvature properties.
method Analyzing hypersurfaces on complex quadrics with at most five distinct constant principal curvatures.
result All classified hypersurfaces are open parts of homogeneous examples.
The study examines principal directions and curvatures of Lagrangian submanifolds.
problem Understanding the geometry of Lagrangian submanifolds.
method Recalling and analyzing the extrinsic principal tangential and normal directions, and their corresponding curvatures for Lagrangian submanifolds in complex Euclidean spaces.
result Established natural relationships between distinguished tangential and normal directions and their curvatures for Lagrangian submanifolds.
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 …
The well known Chen's conjecture on biharmonic submanifolds states that a biharmonic submanifold in a Euclidean space is a minimal one ([10-13, 16, 18-21, 8]). For the case of hypersurfaces, we know that Chen's conjecture is true for biharmonic surfaces in E3 ([10], [24]), biharmonic hypersurfaces in $\mathb…
If M is an isoparametric hypersurface in a sphere Sn with four distrinct principal curvatures, then the principal curvatures κ1,...,κ4 can be ordered so that their multiplicities satisfy m1=m2 and m3=m4, and the cross-ratio r of the principal curvatures (the Lie curvature) equals -1. In this paper, w…
We classify all rotational surfaces in Euclidean space whose principal curvatures κ1 and κ2 satisfy the linear relation κ1=aκ2+b, where a and b are two constants. We give a variational characterization of these surfaces in terms of its generating curve. As a consequence of our classification, we find clos…
The paper shows nearly-Fuchsian properties for certain hyperbolic 3-manifolds.
problem Characterizing hyperbolic 3-manifolds with specific surface properties.
method Analyzing minimal and non-minimal surfaces with principal curvatures in [-1,1](-1,1).
result Weakly almost-Fuchsian manifolds are nearly-Fuchsian.
The study characterizes Clifford hypersurfaces in terms of curvature constants.
problem Characterizing Clifford hypersurfaces in terms of curvature constants.
method Defined constants σ_k and used integral inequalities to show bounds on curvature.
result For specific conditions, σ_k ≥ n^k, with equality for Clifford hypersurfaces.
We study parabolic linear Weingarten surfaces in hyperbolic space $\rlopezh^3$. In particular, we classify two family of parabolic surfaces: surfaces with constant Gaussian curvature and surfaces that satisfy the relation aκ1+bκ2=c, where κi are the principal curvatures, and a,b and c are constant.
The study proves properties of optimizers for sets maximizing perimeter under fixed volume constraints.
problem Existence and properties of bounded convex sets in Riemannian manifolds maximizing perimeter under fixed volume constraints.
method Analyzes the properties of optimizers for sets maximizing perimeter under fixed volume constraints in Euclidean, spherical, and hyperbolic spaces.
result Proves that there are no C2-maximisers of perimeter with prescribed volume and that the smallest principal curvature is constant in regions where the set is of class C2. In this paper, we have studied biharmonic hypersurfaces in space form Mˉn+1(c) with constant sectional curvature c. We have obtained that biharmonic hypersurfaces Mn with at most three distinct principal curvatures in Mˉn+1(c) has constant mean curvature. We also obtain the full classificatio…
Lie minimal surfaces are characterized by differential equations of principal curvatures.
problem Characterizing Lie minimal surfaces in Riemannian space forms.
method Using Euler-Lagrange equations and differential equations of principal curvatures.
result Rotational surfaces are found for certain relationships between principal curvatures.
Principal binets generalize curvature line surfaces to square lattices and are a discrete integrable system.
problem Discretizing curvature line surfaces on square lattices.
method Showed principal binets as a multi-dimensional consistent system.
result Principal binets generalize to higher-dimensional square lattices and are integrable.
We classify all real hypersurfaces with constant principal curvatures in the complex hyperbolic plane.
The paper proves a stronger Petersen--Wilhelm conjecture for principal bundles.
problem Conditions for positive sectional curvature submersion metrics on principal bundles.
method Cheeger deformations, good triples, Chaves-Derdzinski-Rigas type condition.
result Any principal bundle over a positively curved base admits a metric of positive sectional curvature if the submersion is fat.
An almost Fuchsian 3-manifold is a quasi-Fuchsian manifold which contains an incompressible closed minimal surface with principal curvatures in the range of (−1,1). Such a 3-manifold M admits a foliation of parallel surfaces, whose locus in Teichmüller space is represented as a path γ, we show that γ joins the …
The study examines connections and their curvatures on different types of bundles.
problem Understanding connections and curvatures on various bundle types.
method Analysis of connections and curvatures on fiber, principal, and vector smooth bundles.
result Investigations into the relationships between connections and curvatures on different bundle types.