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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.

168,694 papers · 148 categories

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58116174232 · Jun 202019922001200920172026
48 results for Iterative polar decomposition

Study optimizes estimation of orthogonal and rotation matrices from noisy data.

problem Estimating orthogonal and rotation matrices from noisy data.
method Iterative polar decomposition algorithm initialized by spectral methods.
result Algorithm achieves optimal error rate of $(1+o(1)) rac{σ^2 d(d-1)}{2np}$.

Geometrically studies Moore-Penrose inverse and polar decomposition continuity.

problem Continuity of Moore-Penrose inverse for perturbations by operator ideals.
method Geometric construction using essential codimension and Banach-Lie group action.
result Moore-Penrose inverse is a real analytic map between manifolds.

We prove that a polar foliation of codimension at least three in an irreducible compact symmetric space is hyperpolar, unless the symmetric space has rank one. For reducible symmetric spaces of compact type, we derive decomposition results for polar foliations.

2012-04-13abs ↗pdf ↗

We introduce polar metrics on a product manifold, which have product and warped product metrics as special cases. We prove a de Rham-type theorem characterizing Riemannian manifolds that can be locally decomposed as a product manifold endowed with a polar metric. For a product manifold endowed with a polar metric, our …

2013-06-14abs ↗pdf ↗

The paper describes a fine representation of the Ricci tensor and Hessian on RCD spaces.

problem Understanding the structure of the Ricci tensor and Hessians on RCD spaces.
method Polar decomposition of the Ricci tensor and Hessians, providing regularity results.
result The Ricci tensor and Hessians on RCD spaces can be represented by a polar decomposition, revealing their regularity.

The paper explores totally geodesic submanifolds in SPD matrices and their properties.

problem Characterizing and understanding totally geodesic submanifolds in SPD matrices.
method Detailed geometric analysis and projection properties of SPD matrices.
result A non-linear projection on totally geodesic submanifolds has the minimizing property.

Paper uses ResUNet-CMB to reconstruct cosmic polarization rotation from CMB data.

problem Reconstructing anisotropic cosmic polarization rotation from CMB data.
method Extended ResUNet-CMB to handle gravitational lensing and patchy reionization.
result ResUNet-CMB outperforms standard quadratic estimator in reconstructing all three effects.

Parabolic structures with rational weights encode certain iterated blowups of geometrically ruled surfaces. In this paper, we show that the three notions of parabolic polystability, K-polystability and existence of constant scalar curvature Kähler metrics on the iterated blowup are equivalent, for certain polarizations…

2013-03-10abs ↗pdf ↗

In this work, we introduce a deep learning-based polar code construction algorithm. The core idea is to represent the information/frozen bit indices of a polar code as a binary vector which can be interpreted as trainable weights of a neural network (NN). For this, we demonstrate how this binary vector can be relaxed t…

2019-09-26abs ↗pdf ↗

Neural network implementation of Brenier's polar factorization for vector fields.

problem Implementing Brenier's polar factorization theorem for vector fields using neural networks.
method Parameterizing the convex function uu as an input convex neural network and estimating the measure-preserving map MM.
result Practical neural implementation of Brenier's polar factorization theorem.

In this paper, we introduce the notions of an iterated planar Lefschetz fibration and an iterated planar open book decomposition and prove the Weinstein conjecture for contact manifolds supporting an open book that has iterated planar pages. For n1n\geq 1, we show that a (2n+1)(2n+1)-dimensional contact manifold MM suppor…

2017-10-20abs ↗pdf ↗

Decomposes Q-Fano Kähler-Einstein varieties into simpler components.

problem Understanding the structure of Q-Fano Kähler-Einstein varieties.
method Proves decomposition theorem using algebraically integrable foliations and stability conditions.
result Q-Fano Kähler-Einstein varieties decompose into simpler components.

Study on spin random fields using chaos decomposition for cosmic microwave background modeling.

problem Modeling polarization of Cosmic Microwave Background using spin random fields.
method Explicit Wiener-Itô chaos decomposition of area measures of level sets.
result Reveals a clear difference between high frequency regime and zero spin case.

On a polarized manifold (X,L)(X,L), the Bergman iteration φk(m)φ_k^{(m)} is defined as a sequence of Bergman metrics on LL with two integer parameters k,mk, m. We study the relation between the Kähler-Ricci flow φtφ_t at any time t0t \geq 0 and the limiting behavior of metrics φk(m)φ_k^{(m)} when m=m(k)m=m(k) and the ratio m/km/k ap…

2016-06-09abs ↗pdf ↗

A triple space is a homogeneous space G/HG/H where G=G0×G0×G0G=G_0\times G_0\times G_0 is a threefold product group and HG0H\simeq G_0 the diagonal subgroup of GG. This paper concerns the geometry of the triple spaces with $G_0=\SL(2,\R)$, $\SL(2,\C)$ or $\SO_e(n,1)$ for n2n\ge 2. We determine the abelian subgroups AGA\subset G

2013-01-03abs ↗pdf ↗

Using Seiberg-Witten theory, it is shown that any Kaehler metric of constant negative scalar curvature on a compact 4-manifold M minimizes the L^2-norm of scalar curvature among Riemannian metrics compatible with a fixed decomposition H^2(M)=(H^+) + (H^-). This implies, for example, that any such metric on a minimal ru…

1995-06-05abs ↗pdf ↗

A machine learning model for PMD compensation in dual-polarization systems.

problem Compensating for polarization-mode dispersion (PMD) in dual-polarization systems.
method Model-based machine learning approach using the split-step Fourier method for the Manakov-PMD equation.
result The model converges to within 1% of peak dB performance after 428 iterations, achieving a 0.30 dB reduction in effective signal-to-noise ratio compared to PMD-free case.

New recommendations improve Gaussian process accuracy and stability.

problem Numerical instabilities and poor test likelihoods in iterative Gaussian process learning.
method Investigated CG tolerance, preconditioner rank, and Lanczos decomposition rank. Recommended small CG tolerance and large root decomposition size.
result L-BFGS-B optimizer achieves convergence with fewer gradient updates, improving Gaussian process accuracy.

Derives formulas for Monge-Ampère measures and reduces complex conjectures to simpler existence problems.

problem Complex Monge-Ampère measures and their applications in algebraic geometry.
method Derives formulas and reduces conjectures to simpler existence problems.
result Reduces uniform Yau-Tian-Donaldson conjecture to existence of approximate decompositions.

Paper refutes conjecture on tensor power iteration convergence in overcomplete models.

problem Understanding convergence of tensor power iteration in overcomplete random tensors.
method Analysis of tensor power iteration dynamics from random initialization.
result Polynomially many steps are necessary for convergence, refutes logarithmic conjecture.

This paper introduces an acceleration structure for hyperbolic embeddings.

problem Efficiently embedding and visualizing high-dimensional data in hyperbolic spaces.
method Building upon a polar quadtree, the paper introduces a new acceleration structure for hyperbolic embeddings.
result The new method computes embeddings in significantly less time compared to existing methods.

This paper uses Gaussian mixtures to mimic interactions in large language models.

problem Simulating interactions in large language models (LLMs) is computationally expensive.
method Developed an interacting Gaussian mixture model (GMM) system to mimic LLM interactions.
result The interacting Gaussian mixture model system can generate, exchange, and update data and parameters efficiently.

We classify the polar actions on the complex hyperbolic plane up to orbit equivalence. Apart from the trivial and transitive polar actions, there are five polar actions of cohomogeneity one and four polar actions of cohomogeneity two.

2011-08-02abs ↗pdf ↗

The paper studies how Kähler polarizations degenerate to mixed polarizations on toric varieties.

problem Degeneration of Kähler polarizations to mixed polarizations on toric varieties.
method Constructing polarizations by Hamiltonian actions, finding one-parameter families of Kähler polarizations, and analyzing convergence of spaces of holomorphic sections.
result Kähler polarizations degenerate to mixed polarizations as kk increases, with specific convergence results for one-parameter families.

The paper bounds generalization error for iterative learning with bounded updates.

problem Generalization error of iterative learning algorithms with bounded updates for non-convex loss functions.
method Information-theoretic techniques, reformulating mutual information as update uncertainty, variance decomposition.
result Improved generalization error bounds for iterative learning algorithms with bounded updates.

Polarized and GG-polarized CR manifolds are smooth manifolds endowed with a double structure: a real foliation $\Cal F$ (given by the action of a Lie group GG in the GG-polarized case) and a transverse CR distribution (E,J)(E,J). Polarized means that (E,J)(E,J) is roughly speaking invariant by $\Cal F$. Both structures ar…

2012-12-03abs ↗pdf ↗

A polarity of a projective plane is a map, often assumed to be involutive, mapping a generic point to a generic line and reciprocally. The most classical polarity is the polarity with respect to a conic, but other exist: the harmonic polarity with respect to a triangle, the polarities with respect to high-degree algebr…

2013-02-07abs ↗pdf ↗

The generic fiber of a Lagrangian fibration on an irreducible holomorphic symplectic manifold is an abelian variety. Associate a polarization type to such Lagrangian fibrations coming from polarizations on a generic fiber. We prove that this polarization type is constant in families of Lagrangian fibrations. Further, w…

2015-01-19abs ↗pdf ↗

NA0_0CT2^2 improves tensor regression predictions with 0\ell_0 regularization.

problem Improving tensor regression predictions with structural information.
method Noise-Augmented 0\ell_0 regularization on Tucker decomposition.
result Achieves exact 0\ell_0 regularization on core tensor in linear and generalized linear tensor regression.

Structured sparsity is an important modeling tool that expands the applicability of convex formulations for data analysis, however it also creates significant challenges for efficient algorithm design. In this paper we investigate the generalized conditional gradient (GCG) algorithm for solving structured sparse optimi…

2014-10-17abs ↗pdf ↗

The study introduces polarization of generalized Nijenhuis torsions and their relevance in operator fields.

problem Characterization of Haantjes C(M)C^{\infty}(M)-modules of operator fields.
method Introducing polarization of generalized Nijenhuis torsions and proving algebraic identities.
result Polarizations of generalized Nijenhuis torsions are relevant in the characterization of Haantjes C(M)C^{\infty}(M)-modules of operator fields.

Tensor CANDECOMP/PARAFAC (CP) decomposition has wide applications in statistical learning of latent variable models and in data mining. In this paper, we propose fast and randomized tensor CP decomposition algorithms based on sketching. We build on the idea of count sketches, but introduce many novel ideas which are un…

2015-06-14abs ↗pdf ↗

Study geodesic X-ray transforms on hyperbolic surfaces, proposing new reconstruction methods.

problem Inverting geodesic X-ray transforms for symmetric tensor fields on asymptotically hyperbolic surfaces.
method Developed a decomposition theorem for m-tensor fields, used Guillemin-Kazhdan operators and 0-calculus, and provided explicit reconstruction methods.
result Explicit reconstruction methods for even tensor fields from their X-ray transform or normal operator.

Assume that a projective variety together with a polarization is uniformly K-stable. If the polarization is canonical or anti-canonical, then the projective variety is uniformly K-stable with respects to any polarization sufficiently close to the original polarization.

2017-09-24abs ↗pdf ↗