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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.

169,051 papers · 148 categories

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3.3%6.6%9.9%13.2% · Feb 199919922001200920172026
48 results for isotropic non-homogeneous tori

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}.

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 proves only origin-centered spheres solve certain curvature problems.

problem Proving uniqueness of solutions to curvature problems.
method Using the Heintze-Karcher inequality, the study proves the uniqueness of smooth, strictly convex solutions to a class of Minkowski type problems.
result Only origin-centered spheres solve isotropic and LpL_p-Gaussian-Minkowski problems.

Solves Nekhoroshev's problem on invariant tori for Hamiltonian systems with cyclic variables.

problem Finding invariant isotropic tori under Hamiltonian phases flows with involution Hamilton functions.
method Constructs monodromy operator and provides conditions for existence and uniqueness of complex germ without simple spectrum condition.
result Full solution to Nekhoroshev's problem, including Hamiltonian systems with cyclic variables.

New findings on minimal isometric immersions of flat n-tori into spheres.

problem Conditions for minimal isometric immersions of flat n-tori into spheres.
method Analyzes rationality conditions and derives upper bounds for algebraic irrationality degree.
result Upper bound for algebraic irrationality degree of minimal isometric immersions is sharp and equals 4 for n=3.

We consider smooth isotropic immersions from the 2-dimensional torus into R2nR^{2n}, for n2n \geq 2. When n=2n = 2 the image of such map is an immersed Lagrangian torus of R4R^4. We prove that such isotropic immersions can be approximated by arbitrarily C0C^0-close piecewise linear isotropic maps. If n3n \geq 3 the piece…

2018-02-23abs ↗pdf ↗

This article shows that every non-isotropic harmonic 2-torus in complex projective space factors through a generalised Jacobi variety related to the spectral curve. Each map is composed of a homomorphism into the variety and a rational map off it. The same ideas allow one to construct (pluri)-harmonic maps of finite ty…

1999-06-11abs ↗pdf ↗

GD iterates for non-homogeneous deep nets increase margin and converge in direction.

problem Understanding implicit bias in non-homogeneous deep networks.
method Characterization of GD iterates' properties starting from small empirical risk.
result GD iterates converge in direction despite diverging norms, satisfying KKT conditions.

To each non-isotropic almost-complex immersion of a 2-torus into S6 S ^ 6 we associate an algebraic curve, called the spectral curve, and a linear flow in the intersection of two Prym varieties on this spectral curve. We show that generically the spectral curve is smooth and compute the dimension of the moduli space o…

2008-05-24abs ↗pdf ↗

High frequency limit for most of wave phenomena is known as quasiclassical limit or ray optics limit. Propagation of waves in this limit is described in terms of wave fronts and rays. Wave front is a surface of constant phase whose points are moving along rays. As it appears, their motion can be described by Hamilton e…

2001-08-23abs ↗pdf ↗

Study non-homogeneous operators in 1+0 systems, classifying and analyzing their geometric properties.

problem Classify and analyze geometric properties of non-homogeneous operators in 1+0 systems.
method Complete classification of Casimir functions, tensorial criteria for compatibility, bi-pencils definition.
result Found geometric connections with Nijenhuis geometry, proving compatibility results.

New algorithm optimizes complex model selection for non-homogeneous hidden Markov models.

problem Complex combinatorial optimization problem for model selection in NHHMMs.
method Adaptive simulated annealing EM algorithm (ASA-EM).
result Joint optimization of models and parameters for a criterion of interest.

We classify smooth locally free actions of the real affine group on closed orientable three-dimensional manifolds up to smooth conjugacy. As a corollary, there exists a non-homogeneous action when the manifold is the unit tangent bundle of a closed surface with a hyperbolic metric.

2007-02-27abs ↗pdf ↗

Study how regularization and optimization affect margin in deep models.

problem Understanding margin maximization in deep learning models.
method Analyze the limit of loss minimization with diverging norm constraints and margin paths.
result Discovers lexicographic max-margin solutions for homogeneous models and shows convergence under certain conditions.

Capillarity functionals are parameter invariant functionals defined on classes of two-dimensional parametric surfaces in R3 as the sum of the area integral and a non homogeneous term of suitable form. Here we consider the case of a class of non homogenous terms vanishing at infinity for which the corresponding capillar…

2016-08-03abs ↗pdf ↗

Large GD stepsizes improve margins and speed up training for non-homogeneous networks.

problem Training efficiency and margin improvement in non-homogeneous two-layer networks.
method Investigation of two distinct phases in GD training, showing margin growth and empirical risk decrease.
result Large GD stepsizes lead to faster convergence and improved margins in non-homogeneous networks.

In this paper we extend the classical theory of combinatorial manifolds to the non-homogeneous setting. NH-manifolds are polyhedra which are locally like Euclidean spaces of varying dimensions. We show that many of the properties of classical manifolds remain valid in this wider context. NH-manifolds appear naturally w…

2011-08-24abs ↗pdf ↗

The twistor space of the sphere S^{2n} is an isotropic Grassmannian that fibers over S^{2n}. An orthogonal complex structure on a subdomain of S^{2n} (a complex structure compatible with the round metric) determines a section of this fibration with holomorphic image. In this paper, we use this correspondence to prove t…

2009-05-22abs ↗pdf ↗

The paper studies a curvature flow on hypersurfaces in R^(n+1).

problem Analyzing the long-term behavior of a specific type of curvature flow.
method Examining a flow defined by a non-homogeneous anisotropic speed function.
result The flow converges to a sphere for star-shaped and k-convex initial hypersurfaces.

This study explains how adversarial interaction creates non-homogeneous patterns using a pseudo-Reaction-Diffusion model.

problem Understanding how adversarial interaction leads to non-homogeneous patterns in systems.
method Developed a pseudo-Reaction-Diffusion model to explain the mechanism.
result Turing instability is involved in creating non-homogeneous patterns.

Researchers create non-homogeneous finite-volume ends on quaternionic Kähler manifolds.

problem Constructing non-homogeneous quaternionic Kähler manifolds with finite volume ends.
method Using cohomogeneity one deformation of symmetric spaces, the researchers constructed manifolds with specific fundamental groups.
result The constructed manifolds are aspherical and have finite volume ends, not locally homogeneous.

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.

The paper introduces a new insurance pricing model based on driving mileage.

problem Weak link between insurance premiums and mileage, leading to overdriving and accidents.
method Developed a Pay-As-You-Drive insurance pricing model using a counting process and non-homogeneous Poisson distribution.
result The model provides theoretical results for better insurance pricing based on driving behavior.

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 Lagrangian formalism on a arbitrary non-fibrating manifold is considered. The kinematical description of this generic situation is based on the concept of (higher-order) Grassmann manifolds which is the factorization of the regular velocity manifold to the action of the differential group. Here we introduce in this…

1997-09-01abs ↗pdf ↗

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 ↗

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.