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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.

168,695 papers · 148 categories

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99198297396 · May 202619922001200920172026
48 results for Jacobi Star Condition

Study attached submanifolds in solvmanifolds, generalizing symmetric space results.

problem Exploring submanifolds in non-symmetric spaces with unusual curvature properties.
method Generalizing Tamaru's construction to pseudo-Riemannian scalar products and root spaces.
result Ricci curvature restriction holds for attached submanifolds under specific algebraic conditions.

This paper improves linear system solving by optimizing matrix diagonal scaling.

problem Improving the condition number of a matrix for faster iterative methods.
method Left or right diagonal rescaling of the matrix A, with new bounds and algorithms.
result Jacobi preconditioning reduces A's condition number to within a quadratic factor of the best possible scaling.

Defines compatibility between Jacobi structures and pseudo-Riemannian metrics on Jacobi algebroids.

problem Generalizing compatibility between Poisson and pseudo-Riemannian metrics to Jacobi structures.
method Introduces and studies compatibility conditions for Jacobi structures and pseudo-Riemannian metrics on Jacobi algebroids.
result Compatibility conditions are preserved under Poissonization and equivalent to Sasakian structures for contact pseudo-metrics.

This paper connects monetary and star-shaped risk measures by showing their equivalence under certain conditions.

problem Understanding the relationship between monetary and star-shaped risk measures.
method Analyzing the acceptability of 0 and the normalization property.
result Monetary risk measures are only a translation away from star-shapedness under mild conditions.

We use the supergeometric formalism, more precisely, the so-called "big bracket" (for which brackets and anchors are encoded by functions on some graded symplectic manifold) to address the theory of Jacobi algebroids and bialgebroids (following mainly Iglesias-Marrero and Grabowski-Marmo as a guideline). This formalism…

2010-12-13abs ↗pdf ↗

We etablish a necessary and sufficient condition under which there exists a tangential and well graded star product, differential or not, on the dual g^* of a nilpotent Lie algebra g. We also give enlightening examples with explicit computations.

2002-07-22abs ↗pdf ↗

We define the notion of a formal connection for a smooth family of star products with fixed underlying symplectic structure. Such a formal connection allows one to relate star products at different points in the family. This generalizes the formal Hitchin connection introduced by the first author. We establish a necess…

2014-10-07abs ↗pdf ↗

The paper characterizes dynamic return and star-shaped risk measures via BSDEs.

problem Characterizing dynamic return and star-shaped risk measures.
method Characterization of star-shaped functionals and BSDEs.
result Existence of convex BSDEs with non-empty set of supersolutions.

The paper studies Jacobi fields and conjugate points in projective sprays.

problem Investigating Jacobi fields and conjugate points in projective sprays.
method Proved that conjugate points are preserved under projective changes and established conditions for the existence of conjugate points.
result Conditions for the existence of conjugate points in projectively deformed sprays.

The paper establishes conditions for harmonic forms on noncompact manifolds.

problem Conditions for harmonic forms on noncompact manifolds.
method Introducing Condition W and proving conditions for harmonic forms.
result Conditions for harmonic forms on noncompact manifolds are established.

We reformulate the notion of a Jacobi algebroid in terms of weighted odd Jacobi brackets. We then show how a Jacobi algebroid can be understood in terms of a kind of curved Q-manifold. In particular the homological condition on the odd vector field is deformed in a very specific way. This leads to the notion of a quasi…

2011-11-17abs ↗pdf ↗

Paper analyzes Birkhoff relaxation for graph alignment, providing theoretical guarantees.

problem Finding vertex correspondence between two graphs to maximize edge overlap.
method Birkhoff relaxation as a convex relaxation of the quadratic assignment problem (QAP).
result Theoretical guarantees on the performance of Birkhoff relaxation under specific conditions.

This paper extends Jacobi field theory to Jacobi curves and their curvatures.

problem Characterizing and understanding Jacobi curves and their curvatures.
method Developed a new theory of Jacobi curves and associated curvatures, derived Ricci curvature, and presented a Cartan-like theory.
result Jacobi curves are fully characterized by a family of conformal symplectic invariant curvatures.

If W+W_+ denotes the self dual part of the Weyl tensor of any Kähler 4-manifold and SS its scalar curvature, then the relation W+2=S2/6|W_+|^2 = S^2/6 is well-known. For any almost Kähler 4-manifold with S0S \ge 0, this condition forces the Kähler property. A compact almost Kähler 4-manifold is already Kähler if it satisfie…

2006-05-23abs ↗pdf ↗

We study Jacobi structures on the dual bundle AA^\ast to a vector bundle AA such that the Jacobi bracket of linear functions is again linear and the Jacobi bracket of a linear function and the constant function 1 is a basic function. We prove that a Lie algebroid structure on AA and a 1-cocycle φΓ(A)φ\in Γ(A^\ast) indu…

2000-07-24abs ↗pdf ↗

Paper proves non-existence of certain hypersurfaces in complex quadric.

problem Non-existence of Hopf real hypersurfaces with parallel normal Jacobi operator.
method Introducing C\mathcal C-parallel and Reeb parallel normal Jacobi operators, proving non-existence theorems.
result Non-existence of Hopf real hypersurfaces with C\mathcal C-parallel normal Jacobi operator.

Study on stability of 3D sessile drops, identifying degenerate kernel.

problem Linear stability of three-dimensional sessile drops with a free contact line.
method Derived constrained second variation, formulated Jacobi problem, combined geometric and Fourier analysis.
result Kernel of the constrained Jacobi operator is exactly the space of horizontal translations under pressure-volume nondegeneracy.

A variational principle is proposed for obtaining the Jacobi equations in systems admitting a Lagrangian description. The variational principle gives simultaneously the Lagrange equations of motion and the Jacobi variational equations for the system. The approach can be of help in finding constants of motion in the Jac…

2000-05-02abs ↗pdf ↗

Machine learning helps create accurate models of neutron star postmerger signals.

problem Creating accurate postmerger waveforms for binary neutron stars is challenging due to theoretical uncertainties and limited numerical simulations.
method Used a conditional variational autoencoder (CVAE) to construct postmerger models based on numerical-relativity simulations.
result The CVAE can accurately generate postmerger waveforms and encode the neutron star equation of state.

The study shows infinitely many Reeb orbits on star-shaped hypersurfaces with growth rate like prime numbers.

problem Growth rate of Reeb orbits on star-shaped hypersurfaces.
method Analyzing fiberwise star-shaped hypersurfaces in cotangent bundles with topological conditions.
result The number of Reeb orbits with period at most T grows at least like T/log(T).

Algorithm learns weight matrix from single trajectory of nonlinear dynamical system.

problem Learning weight matrix from a single trajectory of nonlinear dynamical system.
method Algorithm uses global stability and well-conditioned covariance to recover weight matrix.
result Algorithm recovers weight matrix with optimal sample complexity and linear running time.

In this paper we discuss a general framework based on symplectic geometry for the study of second order conditions in constrained variational problems on curves. Using the notion of L-derivatives we construct Jacobi curves, which represent a generalization of Jacobi fields from the classical calculus of variations, but…

2018-10-06abs ↗pdf ↗

In the first part of this paper we outline the constructions and properties of Fedosov star product and Berezin-Toeplitz star product. In the second part we outline the basic ideas and recent developments on Yau-Tian-Donaldson conjecture on the existence of Kähler metrics of constant scalar curvature. In the third part…

2019-04-26abs ↗pdf ↗

Study proves radial symmetry of solutions to certain nonlinear equations in space forms.

problem Proving radial symmetry of solutions to nonlinear equations in space forms.
method Establishing Rellich-Pohožaev type identities for Hessian quotient and k-Hessian equations.
result Radial symmetry of solutions for Hessian quotient and k-Hessian equations in space forms.

Let (M,g) be a Riemannian manifold and G a nondegenerate g-natural metric on its tangent bundle T M . In this paper we establish a relation between the Jacobi operators of (M,g) and that of (T M,G). In the case of a Riemannian surface (M,g), we compute explicitly the spectrum of some Jacobi operators of (TM,G) and give…

2009-07-30abs ↗pdf ↗

A unified framework for Poisson and Jacobi structures from 2-covariant tensors

problem Constructing Poisson and Jacobi structures from non-degenerate 2-covariant tensors
method Deriving a formula for the Schouten-Nijenhuis bracket of the associated bivector field
result Recovering classical brackets associated with symplectic, locally conformally symplectic, cosymplectic, and contact geometries

The paper bounds eigenvalues of the Jacobi operator and derives rigidity results for CMC hypersurfaces.

problem Bounding the first eigenvalue of the Jacobi operator for CMC hypersurfaces.
method Geometric upper bounds for eigenvalues and rigidity results.
result New rigidity results for the area and length of CMC hypersurfaces.

Gradient descent with preconditioning finds global optima in overparameterized nonconvex factorization.

problem Finding global optima in nonconvex Burer-Monteiro factorization.
method Preconditioned gradient descent for overparameterized nonconvex function minimization.
result Gradient descent with preconditioning achieves linear convergence in the overparameterized case.

Study magnetic Hamiltonian systems with constraints, deriving Hamilton-Jacobi equations.

problem Understanding dynamics of controlled magnetic Hamiltonian systems with constraints.
method Defined CMH system, derived Hamilton-Jacobi equations for different constraints.
result Invariant solutions of Hamilton-Jacobi equations under CMH-equivalence.

In this paper, we introduce a new commuting condition between the structure Jacobi operator and symmetric (1,1)-type tensor field TT, that is, RξφT=TRξφR_ξφT=TR_ξφ, where T=AT=A or T=ST=S for Hopf hypersurfaces in complex hyperbolic two-plane Grassmannians. By using simultaneous diagonalzation for commuting symmetric operators…

2016-01-25abs ↗pdf ↗

New algorithm for robust density estimation in corrupted data.

problem Density estimation in the presence of adversarial corruption.
method Proposes an algorithm for constructing a density estimator within a star-shaped density class, derived minimax bounds for estimation.
result Obtained minimax upper and lower bounds for density estimation under adversarial corruption.

This paper studies Hamilton-Jacobi equations for magnetic systems with constraints.

problem Understanding dynamics of magnetic systems with geometric constraints.
method Developed Hamilton-Jacobi equations for magnetic systems with nonholonomic constraints.
result Revealed relationships between magnetic structures, constraints, and dynamics.

Improved guarantees for nonconvex matrix factorization with rank overparameterization.

problem Minimizing nonconvex objective over low-rank matrices.
method Overparameterized Burer--Monteiro approach, leveraging smoothness and strong convexity.
result Local optimization globally converges to global optimum under certain rank conditions.

In this paper, we have considered a new commuting condition, that is, (Rξφ)S=S(Rξφ)(R_ξφ) S = S (R_ξφ) \big(resp. $(\Bar{R}_Nφ) S = S (\Bar{R}_Nφ$)\big) between the restricted Jacobi operator~RξφR_ξφ (resp. $\Bar{R}_Nφ$), and the Ricci tensor SS for real hypersurfaces MM in G2(Cm+2)G_2({\mathbb C}^{m+2}). In terms of this condition we…

2014-09-25abs ↗pdf ↗