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arXiv research

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.

169,341 papers · 148 categories

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48 results for harmonic unit vector fields

The paper studies integrability of isotropic almost complex structures and harmonic unit vector fields.

problem Integrability of isotropic almost complex structures and properties of harmonic unit vector fields.
method Introduced isotropic almost complex structures and Liouville 1-forms, defined new metrics and studied harmonic unit vector fields.
result Necessary and sufficient conditions for a unit vector field to be harmonic with respect to the new metrics are obtained.

The study proves biharmonic unit sections on 2-tori are always harmonic and exists in each homotopy class.

problem Characterizing biharmonic unit vector fields and sections on 2-tori.
method Analyzing variational problems for unit vector fields under conformal metrics, proving properties through homotopy classes.
result Biharmonic unit sections on 2-tori are always harmonic and exist in each homotopy class.

Study biharmonic vector fields and unit vector fields on Riemannian manifolds.

problem Determine the equivalence of biharmonicity and harmonicity for vector fields and unit vector fields on Riemannian manifolds.
method Analyze biharmonic vector fields and unit vector fields on (M,g)(M,g) with pseudo-Riemannian gg-natural metrics on TMTM and T1MT_1M.
result Contrary to Sasaki metric, biharmonicity and harmonicity are not equivalent for large classes of gg-natural metrics on TMTM.

Harmonic and minimal great circle fibrations have special Gauss maps.

problem Characterizing Gauss maps of harmonic and minimal great circle fibrations.
method Analyzing the relationship between the Gauss map and the generating unit vector field.
result The Gauss map of a great circle fibration is harmonic (minimal) if and only if the generating unit vector field is harmonic (minimal).

Study on HH-contact structures on Riemannian manifolds.

problem Characterizing HH-contact unit tangent bundles of Riemannian manifolds.
method Analyzing the conditions for a Riemannian manifold to have a HH-contact unit tangent bundle.
result The unit tangent bundle of a Riemannian manifold is HH-contact if and only if the manifold is 22-stein.

The stability of the 3-dimensional Hopf vector field, as a harmonic section of the unit tangent bundle, is viewed from a number of different angles. The spectrum of the vertical Jacobi operator is computed, and compared with that of the Jacobi operator of the identity map on the 3-sphere. The variational behaviour of t…

2000-05-31abs ↗pdf ↗

The isotropic almost complex structures induce a Riemannian metric gδ,σg_{δ,σ} on TM, which are the generalized type of Sasakian metric. In this paper, the Levi-Civita connection of gδ,σg_{δ,σ} is calculated and the harmonicity of unit vector fields from (M,g)(M, g) to (S(M),igδ,0)(S(M), i*g_{δ,0}) is investigated, where igδ,0i*g_{δ,0} is…

2014-12-07abs ↗pdf ↗

Harmonic unit normal sections studied for Grassmannians induced by cross products.

problem Energy of maps assigning unit vectors to subspaces of Grassmannians.
method Analyzing cross products to induce harmonic sections into sphere bundles.
result All unit normal sections of Grassmannians associated with cross products are harmonic.

An almost contact metric structure is parametrized by a section of an associated homogeneous fibre bundle, and conditions for this to be a harmonic section, and a harmonic map, are studied. These involve the characteristic vector field, and the almost complex structure in the contact subbundle. Several examples are giv…

2006-02-23abs ↗pdf ↗

The study explores harmonic vector fields on a specific type of Riemannian Lie group.

problem Characterizing harmonic vector fields on a warped product of a line and a 3D Riemannian Lie group.
method Using a characteristic variational condition, the study applies to the case of a 3D Riemannian Lie group equipped with a left-invariant metric.
result Examples of harmonic vector fields on the warped product that are not left-invariant are provided.

The theory of harmonic vector fields on Riemannian manifolds is generalised to pseudo-Riemannian manifolds. Harmonic conformal gradient fields on pseudo-Euclidean hyperquadrics are classified up to congruence, as are harmonic Killing fields on pseudo-Riemannian quadrics. A para-Kaehler twisted anti-isometry is used to …

2015-01-07abs ↗pdf ↗

The paper characterizes vector fields as interpolating sesqui-harmonic maps on Riemannian manifolds.

problem Characterizing vector fields as interpolating sesqui-harmonic maps on Riemannian manifolds.
method Characterization theorem and critical point condition for interpolating sesqui-harmonic vector fields.
result Conditions for vector fields to be interpolating sesqui-harmonic maps on compact manifolds.

Study on vector fields on Lie groups reveals surprising algebraic coincidences.

problem Characterizing vector fields on Lie groups with Riemannian metrics.
method Algebraic and geometric analysis of left-invariant vector fields on nilpotent Lie groups.
result Spaces of Killing, one-harmonic, and conformal vector fields coincide with the center of the Lie algebra on nilpotent Lie groups.

Study on biharmonic and interpolating sesqui-harmonic vector fields on para-Kähler--Norden manifolds.

problem Investigating higher-order harmonicity in pseudo-Riemannian geometry.
method Deriving first variations of bienergy and interpolating sesqui-energy functionals, characterizing biharmonic and interpolating sesqui-harmonic vector fields.
result Explicit characterizations and examples of vector fields satisfying biharmonic and interpolating sesqui-harmonic conditions.

A vector field s on a Riemannian manifold M is said to be harmonic if there exists a member of a 2-parameter family of generalised Cheeger-Gromoll metrics on TM with respect to which s is a harmonic section. If M is a simply-connected non-flat space form other than the 2-sphere, examples are obtained of conformal vecto…

2013-01-25abs ↗pdf ↗

The absence of interesting harmonic sections for the Sasaki and Cheeger-Gromoll metrics has led to the consideration of alternatives, for example in the form of a two-parameter family of natural metrics shown to relax existence conditions for harmonicity. This article investigates harmonic Killing vector fields, proves…

2007-03-02abs ↗pdf ↗

The paper classifies Ricci solitons and studies harmonic vector fields on a specific Thurston geometry.

problem Classifying Ricci solitons and studying harmonic vector fields in a specific Thurston geometry.
method Left-invariant Riemannian metric classification and analysis of harmonic maps and vector fields.
result All Ricci solitons on (F4,g)(F^4,g) are expanding and non-gradient.

New definitions and properties of harmonic vector fields on Finsler manifolds.

problem Defining and understanding harmonic vector fields in Finsler geometry.
method Natural definitions of differential, divergence, and pp-harmonic form; proving Hodge theorem; Bochner-Yano classification theorem.
result A closed orientable Finsler manifold with a positive harmonic Ricci scalar has a zero Betti number.

We present a new equation with respect to a unit vector field on Riemannian manifold MnM^n such that its solution defines a totally geodesic submanifold in the unit tangent bundle with Sasaki metric and apply it to some classes of unit vector fields. We introduce a class of covariantly normal unit vector fields and pro…

2005-09-30abs ↗pdf ↗

This article studies the harmonicity of vector fields on Riemannian manifolds, viewed as maps into the tangent bundle equipped with a family of Riemannian metrics. Geometric and topological rigidity conditions are obtained, especially for surfaces and vector fields of constant norm, and existence is proved on two-tori.…

2008-09-16abs ↗pdf ↗

Study surfaces in Half-Pipe space and vector fields on hyperbolic plane.

problem Mapping surfaces in Half-Pipe space to vector fields on hyperbolic plane.
method Use harmonic Lagrangian vector fields and infinitesimal Douady-Earle extension.
result Prove existence and uniqueness of harmonic Lagrangian extensions with Zygmund conditions.

Study geometrical properties of oscillator group with a Lorentzian metric.

problem Geometrical analysis of oscillator group.
method Bi-invariant Lorentzian metric, homogeneous Ricci solitons, harmonicity properties, energy functional.
result Determination of critical points for energy functional and explicit calculation of their energy.

Our aim in this paper is to investigate some geometrical properties of Berger Spheres i.e. homogeneous Ricci solitons and harmonicity properties of invariant vector fields. We determine all vector fields which are critical points for the energy functional restricted to vector fields. We also see that do not exist any v…

2014-12-19abs ↗pdf ↗

Study of vortex interactions in Ginzburg-Landau models on 2D Riemannian manifolds.

problem Characterize and quantify interactions between vortices in Ginzburg-Landau models.
method Variational Ginzburg-Landau model, Γ-limit analysis, flux quantization constraints.
result Renormalized energy between vortices determined as a Γ-limit.

We present an explicit formula for the mean curvature of a unit vector field on a Riemannian manifold, using a special but natural frame. As applications, we treat some known and new examples of minimal unit vector fields. We also give an example of a vector field of constant mean curvature on the Lobachevsky (n+1)(n+1) s…

2005-03-24abs ↗pdf ↗

Study finds the volume of unit vector fields on a punctured sphere and shows their images match minimally immersed Klein bottles.

problem Finding the volume of unit vector fields on a punctured sphere.
method Analyzes the volume of unit vector fields on an antipodally punctured unit 2-sphere and shows their images coincide with minimally immersed Klein bottles.
result The images of minimizing vector fields on the punctured sphere match those of minimally immersed Klein bottles.

Minimal surfaces in S3(2) linked to vector fields on punctured sphere.

problem Connecting minimal surfaces in S3(2) to vector fields on a punctured sphere.
method Established a correspondence between minimal surfaces and area-minimizing vector fields.
result Stability relation for Lawson cylinders in S3(2).