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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.

169,181 papers · 148 categories

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149298447596 · Jun 202019922001200920182026
48 results for isotropic states

In the Friedmann Model of the universe, cosmologists assume that spacelike slices of the universe are Riemannian manifolds of constant sectional curvature. This assumption is justified via Schur's Theorem by stating that the spacelike universe is locally isotropic. Here we define a Riemannian manifold as almost locally…

2003-02-19abs ↗pdf ↗

We show that no exotic R4\mathbb{R}^4 admits a complete Riemannian metric with uniformly positive isotropic curvature and with bounded geometry. This is essentially a corollary of the main result in [Hu1], and was stated in [Hu2] without proof. In the process of the proof we also show that the diffeomorphism type of an…

2016-05-03abs ↗pdf ↗

The paper examines Randers metrics with isotropic scalar curvature properties.

problem Characterizing Randers metrics with specific scalar curvature properties.
method Analyzes properties of Randers metrics with isotropic scalar curvature.
result Proves that Randers metrics with weakly isotropic scalar curvature have isotropic SS-curvature and are either Minkowskian or Riemannian.

Paper improves learning efficiency by focusing on effective dimensionality.

problem Dimensionality bottleneck in modern learning tasks.
method Developed tools to reduce dimensional costs using effective dimensionality.
result Uniform concentration bounds involving effective dimensionality, improving over existing results.

Study of invariant surfaces in isotropic and pseudo-isotropic geometries.

problem Prescribed curvature for invariant surfaces in singular metrics.
method Analysis of one-parameter subgroups of isotropic rigid motions, computation of fundamental forms and curvatures.
result Generalization of revolution and helicoidal surfaces to singular metrics.

This paper explores non-periodic folding of Spidron units, revealing nonlinear dynamics.

problem Understanding the kinematics and nonlinear phenomena of Spidron units.
method Analysis of single unit cell kinematics and recursive construction of multiple cells.
result Non-periodic folding restricts isotropic folding as the number of unit cells increases.

Study physical work done by isotropic vector forces along isotropic curves.

problem Investigate physical work done by isotropic vector forces.
method Analyze forces represented by isotropic vectors acting along isotropic curves on a manifold with specific metric structures.
result Calculate the work done by isotropic vector forces along isotropic curves.

The paper develops RM frames for isotropic and pseudo-isotropic spaces and characterizes spherical curves.

problem Differential geometry of curves in isotropic and pseudo-isotropic 3-spaces.
method Developing rotation minimizing frames and applying them to spherical curves in isotropic and pseudo-isotropic spaces.
result Characterization of spherical curves via linear equations involving curvatures and RM frames.

Study of surfaces in isotropic and pseudo-isotropic spaces using Gauss map and shape operator.

problem Differential geometry of surfaces in degenerate metric spaces.
method Introducing isotropic Gauss map and shape operator, computing curvature tensors and geodesics.
result New curvature tensor not vanishing identically, related to relative Gaussian curvature.

In this paper, we construct a new class of Finsler manifolds called generalized isotropic Berwald manifolds which is an extension of the class of isotropic Berwald manifolds. We prove that every generalized isotropic Berwald manifold is a generalized Douglas-Weyl manifold. On a compact generalized isotropic Berwald man…

2013-02-12abs ↗pdf ↗

The study finds conditions for flat isotropic non-homogeneous tori to be Hamiltonian minimal.

problem Finding conditions for Hamiltonian minimality of isotropic non-homogeneous tori.
method Constructing a family of flat isotropic non-homogeneous tori and finding necessary and sufficient conditions.
result Necessary and sufficient conditions for Hamiltonian minimality of isotropic non-homogeneous tori in Hn\mathbb{H}^n and CP2n+1\mathbb{C} \mathrm{P}^{2n+1}.

Spinor representation in isotropic space via Laguerre geometry.

problem Representing conformal and constant mean curvature surfaces in isotropic space.
method Developing Laguerre geometry of isotropic space, defining spin transformations, and constructing Weierstrass and Kenmotsu representations.
result Explicit constructions of zero mean curvature and constant mean curvature surfaces.

The paper studies hanging chains and surfaces in degenerate geometries.

problem Investigating hanging chains and surfaces in simply isotropic plane and space.
method Characterizing catenaries and proving them as minimal surfaces in the simply isotropic space.
result The simply isotropic catenary is the generating curve of a minimal surface of revolution.

Study on uniquely determining thermal properties from boundary temperature and heat flux measurements.

problem Determine thermal conductivity and volumetric heat capacity from boundary measurements.
method Uniqueness proof for isotropic and anisotropic media under thermal diffusivity assumption.
result Uniqueness of thermal properties in all dimensions and up to a gauge in two dimensions.

The paper approximates smooth isotropic surfaces with piecewise linear ones.

problem Approximating smooth isotropic surfaces with piecewise linear ones.
method Using analogies with infinite dimensional moment map geometry, the authors prove the approximation of smooth isotropic immersions by piecewise linear ones.
result Smooth isotropic immersions can be approximated by piecewise linear isotropic maps.

In this paper we will show that a Lagrangian, Lorentzian surface M12M^2_1 in a complex pseudo space form M~12(4c)\widetilde M^2_1 (4c) is pseudo-isotropic if and only if MM is minimal. Next we will obtain a complete classification of all Lagrangian, Lorentzian surfaces which are lightlike pseudo-isotropic but not pseudo-isot…

2016-10-05abs ↗pdf ↗

We show that for m>n2m>n\geq 2, there are at least two exact isotropic nn-tori in Cm\mathbb{C}^m which are not Hamiltonian isotopic in Cm\mathbb{C}^m, even though they are smoothly isotopic as isotropic nn-tori. We apply this discovery to obtain more distinct non-exact isotropic tori in Cm\mathbb{C}^m.

2016-03-30abs ↗pdf ↗

Study classifies zero mean curvature surfaces with planar curvature lines.

problem Characterizing surfaces with specific curvature properties.
method Complete classification and investigation of their relationship to Thomsen-type surfaces.
result Zero mean curvature surfaces with planar curvature lines belong to a 1-parameter family.

The study of Laguerre isotropic hypersurfaces with rigidity and isoparametric properties.

problem Characterizing and understanding Laguerre isotropic hypersurfaces.
method Analyzing hypersurfaces with zero Laguerre form and constant eigenvalues of the Laguerre tensor.
result For L-isotropic hypersurfaces, if they are also L-isoparametric, the constant λλ must be zero.

This paper aims to provide a description of totally isotropic Willmore two-spheres and their adjoint transforms. We first recall the isotropic harmonic maps which are introduced by Hélein, Xia-Shen and Ma for the study of Willmore surfaces. Then we derive a description of the normalized potential (some Lie algebra valu…

2016-04-10abs ↗pdf ↗

This work extends holomorphic surface representations to isotropic space.

problem Representing minimal surfaces in simply isotropic space with degenerate metrics.
method Developed new forms of Weierstrass and Björling representations for isotropic minimal surfaces.
result Holomorphic representations of isotropic minimal surfaces are achieved.

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.

Paper classifies Randers metrics based on Ricci curvature properties.

problem Investigating isotropic projective Ricci curvature in Randers metrics.
method Classification of Randers metrics based on isotropic projective Ricci curvature properties.
result Randers metric of isotropic projective Ricci curvature is reversible if and only if it is of square projective Ricci curvature.

The study finds compact vacuum static spaces with positive isotropic curvature are spheres or products of a circle and sphere.

problem Characterizing compact vacuum static spaces with positive isotropic curvature.
method Proving isometric equivalence to spheres or product spaces.
result Compact vacuum static spaces with positive isotropic curvature are isometric to spheres or product spaces.

Let Rn+1,nR^{n+1, n} be the vector space R2n+1R^{2n+1} equipped with the bilinear form (X,Y)=XtCnY(X,Y)=X^t C_n Y of index nn, where Cn=i=12n+1(1)n+i1ei,2n+2iC_n= \sum_{i=1}^{2n+1} (-1)^{n+i-1} e_{i, 2n+2-i}. A smooth γ:RRn+1,nγ: R\to R^{n+1,n} is {\it isotropic} if γ,γx,,γx(2n)γ, γ_x, \ldots, γ_x^{(2n)} are linearly independent and the span of γ,,γx(n1)γ, \ldots, γ_x^{(n-1)} is …

2016-08-26abs ↗pdf ↗

The study examines surfaces in isotropic space with specific Gauss map properties.

problem Understanding surfaces in simply isotropic space with degenerate metric.
method Investigates surfaces with Gauss map coordinates as eigenfunctions of the Laplace-Beltrami operator for minimal and parabolic normals.
result Identifies surfaces characterized by eigenfunction properties of the Gauss map.

The paper classifies almost isotropic Kähler manifolds, proving their properties.

problem Classifying almost isotropic Kähler manifolds.
method Analyzing Jacobi operators and their ranks.
result Almost isotropic Kähler manifolds of dimension d=2n4d=2n \geq 4 are isometric to complex projective space, complex hyperbolic space, or totally geodesically foliated by leaves isometric to Cn1\mathbf{C}^{n-1}.

The paper studies conformally flat cubic metrics with isotropic curvature, finding they must be Minkowski.

problem Understanding conformal properties of cubic metrics with isotropic scalar curvature.
method Analyzing the conformal flatness and isotropic scalar curvature of cubic metrics.
result Cubic metrics with weakly isotropic scalar curvature must be Minkowski metrics.

In this paper, we study the second approximate Matsumoto metric on a manifold M. We prove that F is of scalar flag curvature and isotropic S-curvature if and only if it is isotropic Berwald metric with almost isotropic flag curvature.

2014-07-31abs ↗pdf ↗

The paper bounds bandwidth and focal radius for manifolds with positive isotropic curvature.

problem Bounding bandwidth and focal radius for manifolds with positive isotropic curvature.
method Using spectral properties of a twisted de Rham-Hodge operator.
result Upper bounds on bandwidth and focal radius are derived for hypersurfaces in PIC manifolds.

Study on translation hypersurfaces with constant curvature in 4D isotropic space.

problem Investigate translation hypersurfaces with constant curvature in 4D isotropic space.
method Analyze hypersurfaces generated by translating curves in perpendicular isotropic planes.
result Identify four non-equivalent types of translation hypersurfaces with constant curvature in 4D isotropic space.

The isotropic 3-space I^3 which is one of the Cayley--Klein spaces is obtained from the Euclidean space by substituting the usual Euclidean distance with the isotropic distance. In the present paper, we give several classifications on the surfaces in I^3 with the constant relative curvature (analogue of the Gaussian cu…

2016-01-13abs ↗pdf ↗